This is an update for anyone else having the same problems. I've solved this problem with a little help from a few other websites.The complete steps are below after the intro.
TunnelBlick: https://code.google.com/p/tunnelblick/
OVPN files from TunnelBear: https://www.tunnelbear.com/development/linux_support/
For the configurations check out this awesome post: http://rodrigo.sharpcube.com/2010/06/20/using-and-sharing-a-vpn-connection-on-yo ur-mac/
Intro:
First, I've confirmed with TunnelBear customer support that L2TP is too slow to really work for my uses. From the TunnelBear support bears: "L2TP is an alternative way of connecting to our servers, the normal app version connects via OpenVPN which is a different protocol and quite a bit faster. Unfortunately this is a side effect of the current workaround we are using coupled with the fact that you'll always see some kind of speed drop with a VPN connection as is."
As an aside, I'd like to say that the TunnelBear support services were great! They gave me all the advance configuration settings I needed to make the L2TP configuration work. Still, the L2TP settings weren't enough to make the connection strong enough. So, I needed a new workaround that actually let's me manually route through the MacBook Air without using the "Share My Internet" connection. So here are the steps to make your TunnelBear Giant or Grizzly account work with an Apple TV abroad. Please note, I don't think these settings will work with a free account.
Step 1:
You need to connect your Apple TV and MacBook to the same router or hub using ethernet cables, as far as I know, this will not work over WiFi. AirPlay over WiFi will still work as long as the AppleTV is on the same network that is creating the WiFi.
Step 2:
Download TunnelBlick (for Mavericks you might need the beta version, depending on what's been recently released, this is a free download) and the OpenVNPconfigurationfiles from TunnelBear (zip file). Don't yet install TunnelBlick.
Step 3:
Unzip the TunnelBear Configuration files, and move this entire unzipped directory to wherever you want it to permanently live your machine. If you want to connect your Apple TV to a US server located the following file in the TunnelBear unzipped directory from Step 2: "TunnelBear United States.ovpn". Duplicate this file, and rename it "TunnelBear United States_push.ovpn". If you want to use a different server (UK, for example), just choose the UK ovpn file.
Step 4:
Open "TunnelBear United States_push.ovpn" with TextEdit (right-click --> Open With --> Other --> TextEdit.app). Once you have the file open, add the following line to the file at the end:
push "redirect-gateway def1"
including the "". Save and close the file. To read about what this add in does, see the OpenVPN.net guide.
Step 5:
Install TunnelBlick, when prompted, enter your admin passwords to install the application. When TunnelBlick asks you if you have configuration files, select yes. Once TunnelBlick is installed and running, locate the "TunnelBear United States_push.ovpn" file and double click it. This should launch TunnelBlick and ask you for your user name and password. Here enter the password and user name that you used for your TunnelBear Giant or Grizzly account (email and password, usually). At this point TunnelBlick should have confirmed that you have successfully connected to the server, if it is not connect check your regular Internet connection, and your user name and password for TunnelBear.
Step 6:
Now that you've successfully connected to the VPN on your Mac, you need to make a few more changes to let you share this connection with your Apple TV. Namely, you need to turn your MacBook into a gateway. For most of the next steps, I used this great guide.
Open your favorite text editor and create a new file. Paste the following lines in it:
#!/bin/sh
natd -interface tun0
ipfw -f flush
ipfw add divert natd ip from any to any via tun0
ipfw add pass all from any to any
sysctl -w net.inet.ip.forwarding=1
Save this file as "natvpn.sh". Make sure this is a text only file, and not a rich text document.
Step 7:
Now you need to make your new shell file executable. So, open up Terminal. Navigate to the folder where you made your natvpn.sh file (if you are new to Terminal, try Apple's guide). Once you are in the same directory as natvpn.sh, inenter:
chmod 755 natvpn.sh
This is the command for Mavericks. For pervious versions of OSX this command may be different. At this point, you should connect to the TunnelBear server using TunnelBlick, if you are not already connected.
Step 8:
Now that you have your shell file as executable, in Terminal enter:
sudo ./natvpn.sh
It will prompt you for your system password and may give you a warning, enter password and hit enter. If all is going well, Terminal should output:
Flushed all rules.
00100 divert 8668 ip from any to any via tun0
00200 allow ip from any to any
net.inet.ip.forwarding: 0 -> 1
Hurray! Your MacBook is now working as a gateway. Note: If this didn't happen, you may have Internet sharing turned on in your System Preferences. Make sure this is not on, and try again. Otherwise see the troubleshooting guidelines here.
Step 9:
Now that your MacBook is acting as a gateway, you need to connect your AppleTV through your MacBook. First, you'll need your MacBook's IP address. You can get this via System Preferences --> Network --> select your active ethernet network, and find the IP Address, it should be something like 192.168.0.10. Write down the IP address.
Step 10:
Turn on your AppleTV. It should be hardwired to the same router as your MacBook. As I said above, this will not work over WiFi. On your AppleTV go to Settings --> General --> Network --> Ethernet --> Configure IP --> Manual
The AppleTV should now prompt you to enter several different settings:
IP Address - Don't change this
Subnet Mask - Don't change this
Router - Here enter the IP address of your MacBook air, in our example it will be 192.168.0.10
DNS - Here you should use an Open DNS server of your choice, for GoogleDNS use 8.8.8.8
Step 11:
Once you've entered those settings, your AppleTV should cycle through and apply the changes. Sometimes, you have to restart your AppleTV to make it work (not always). Once this is done, your AppleTV should be using your MacBook as a gateway and you should be able to use Netflix, Hulu Plus, or whatever you want over your VPN.
Some Notes:
If you reset your network, the IP address of your MacBook may change, in which case you need to reconfigure your Apple TV. If you restart your computer, your IP address might change also, and you'll need to reconfigure the Apple TV. Also, if you turn off your VPN network, your Apple TV will stop working. Also, when you restart your MacBook, you may need to rerun the "natvpn.sh" file. For advanced trouble shooting, check out this article. If you have other questions, ask me below.