Sure it's possible on wireless, I tried it. But did not try it on vista though (or vista with XP). But I'm almost certain that it should work, if not by default, you might need to tweak your firewall and remote users settings for it.
You can remote out from Vista Home Basic but can't remote in. Same with Vista Home Premium. There is a hack that will modify the registry and replace some DLLs in Vista Home Premium to allow you to remote desktop in, though.
I am running Vista Ultimate( no SP1), and RDC(mstsc) is working fine from Vista to XP and from XP to Vista.
In vista you need to enable: My Pc - System Properties - Remote Tab - Allow connections from computers.....
You have to enable Remote Desktop in your firewall.