you can wireless tether on 2.2 .. Wireless tether app has many versions and some work better with certain roms than others, Best thing is to try them before you go back to 2.1 , honestly . You need to be rooted but no reason why you cannot find a version of wireless tether to work.Try this link and bookmark it as versions come out often
Downloads - android-wifi-tether - Project Hosting on Google Code
