Hello how can I change the AI's base number of command points? Or for that matter all players in a multiplayer game?

I don't know if it applies to multiplayer but in single player XX under the empire's simulation property list will allow increasing the command points by about XX.

Thanks a lot. I am assuming the AI side will also have their CP increased as well?

The entry is per empire, it goes under each empires \Simulation\Properties element so you can set it different for each (though the last time I played with it was the first beta build though I don't think anything has changed). You will not find it in there by default, I believe it gets added as you get the increase in command point techs. Also I found back then whatever I set it too I'd get that value minus 1 in game. IE I did 43 for myself and was limited to 42, though that might have just been a bug back then like I said I've not played around with it in the last couple builds.