You can play almost any TA Mod on PW as long as all the players got the same unit pack... but u have to specify in the game name that its an AA unit mod game only or something. (unless it's built kinda like Spring which is not exactly a ta mod but a different game engine using TA as a guide if i understand correctly)
Alternately, you can install the AA mod in a seperate copy of TA folder renamed to AA TA and configure/point the phoenix client to to it via the support for one of the other mods. You have to specify to the client were to look for each mod. but nothing prevents you to use the UberHack mod support to point to AA TA folder. (again, as long as you and you AA friends mention/know that the UH game hosted is actually an AA game.) This way you can always chose to play OTA or any other mods without having to switch units packs back in and out of ur OTA folder each time. ;)
PhalanX aka PLU_TyranT aka No_Limits