FaceTime on iPad 2

Can someone confirm that FaceTime can only be used via WiFi?

I have purchased FaceTime for my MBP and used it once from NZ to Aussie by using a friends WifFi network but all my normal internet access is via 3G Data and obviously I have FaceTime on my iPad 2 which is also on a separate 3G data plan.

OK I can and have shared 3G internet via Airport on my Mac for the WiFi only iPad 1. So do I have to share the 3G data through my MBP so I can use FaceTime on my iPad 2? and at the same time not be able to use FaceTime on my Mac ... If so it's a very strange decision for Apple to make.

There are No Mac users around here with FaceTime to try it out with..

Thanks Guys.