The n900 wifi hotspot runs in ad-hoc mode. Most android devices ship with only the ability to see wifi networks in infrastructure mode. I don't believe anyone has successfully gotten the n900 to support infrastructure mode. Try looking up info on getting your tab to support recognizing ad-hoc wifi networks on xda if you are looking to go the wifi route--it could be someone as easy as a file push or something as bad as a custom rom.

In terms of getting bluetooth-pan to work, from the little bit of testing that was done on this thread, it seems like pre-honeycomb versions of android doesn't have that built-in. You could look into seeing if someone has created support for it or ported a version of honeycomb. The 3.2 version of honeycomb that just came out is supposed to support 7" tablets, I believe...