Yeech.
PBW makes no official policy on this sort of thing, as long as it happens in the clear and open. The only behavior will step into and stop is actual cheating where a player is manipulating data files, or playing two empires simultaneously unknown to the other players.
It is the game owners responsibility and say as to whether this sort of thing is allowed. There may be some sort of logical game reason for it. For exapmple if it's a team game.
However, personally I wouldn't like it either if the game owner allowed something like this without making it perfectly clear to the other players what the deal was beforehand. My suggestion is you take it up with him. If you don't get an answer you like you are free to vote with your feet and find a game with an owner mroe receptive to player input. There are plenty of games to chose from on PBW.
Geoschmo
PBW Admin Team