I would like to know if it's possible to play worms world party multiplayer (tcp/ip) with another person AND a computer team. Computer teams do not appear in the list of available teams. It's possible in Worms Armageddon too?

It isn't possible in either game currently. Might be put into WA eventually, but if you look at the list of everything that's planned for the major 4.0 update for it, I think you'll see why support for AI teams in network matches isn't the most hotly anticipated feature. :p