1-Are you talking about the GC version of the game or the GBA version?
2-That emulator (the full name is Visual-Boy Advance) doesn´t need a GBA BIOS image at all to boot a game.
3-(In case it is the GC game) For multiplayer-mode games you just have to use the emulator´s NetPlay function.
4-Before you start to reply and test your problem again, I suggest to take a look at the game´s wiki page.
2-That emulator (the full name is Visual-Boy Advance) doesn´t need a GBA BIOS image at all to boot a game.
3-(In case it is the GC game) For multiplayer-mode games you just have to use the emulator´s NetPlay function.
4-Before you start to reply and test your problem again, I suggest to take a look at the game´s wiki page.