Since this issue was driving me crazy (I use bluetooth alot, with a mouse and headset), I tried to find a fix for it. While it is a hack and in no way official, I think I managed to make one.
I didn't test it extensively, so it might not work perfectly, but from what I tested so far, it seems to fix the issue.
What my solution does, is disable bluetooth before the computer goes to sleep and re-enable it after 5 seconds from waking up from suspend, which give enough time for the wifi to connect without issue.
1. Download Sleepwatcher 2.2 from its website to you website, to your desktop and then run the following commands in a terminal: http://www.bernhard-baehr.de/
$ cd ~/Desktop/
$ sudo mkdir -p /usr/local/sbin /usr/local/share/man/man8
$ sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher /usr/local/sbin
$ sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher.8 /usr/local/share/man/man8
$ sudo cp ~/Desktop/sleepwatcher_2.2/config/de.bernhard-baehr.sleepwatcher-20compatibilit y.plist /Library/LaunchDaemons/
$ launchctl load /Library/LaunchAgents/de.bernhard-baehr.sleepwatcher-20compatibility.plist
2. Download Blueutil from its website and install it: http://www.frederikseiffert.de/blueutil/
3. Create the 2 sleepwatcher scripts, in the terminal type the following commands and copy this content:
$ vi /etc/rc.sleep
#BEGINING OF /etc/rc.sleep. DO NOT COPY THIS LINE
#!/bin/bash
/usr/local/bin/blueutil off
exit 0
#END OF /etc/rc.sleep. DO NOT COPY THIS LINE
$ vi /etc/rc.wakeup
#BEGINING OF /etc/rc.wakeup. DO NOT COPY THIS LINE
#!/bin/bash
$(sleep 5 && /usr/local/bin/blueutil on) &
exit 0
#END OF /etc/rc.wakeup. DO NOT COPY THIS LINE
4. From the terminal, change the permission of the 2 scripts
$ sudo chmod a+x /etc/rc.sleep
$ sudo chmod a+x /etc/rc.wakeup
5. Now, try to suspend and resume your laptop and everything should work correctly