IPad via ad hoc network or bluetooth

you can't do it over bluetooth

ad hoc network guide same deal with all ios devices

http://www.taranfx.com/how-to-connect-iphone-to-mac-adhoc-wireless-without-route r-reverse-tether

Enable Internet Sharing in the System Perefernces on your Mac. No additional software is needed. Make sure you enable Airport as well. You can search the help file when you are in the system preferences and it will define the steps for you.