I believe the Region Free but the Japan 360 only release of Virtual On Force is 2v2 (got a budget "platinum" rerelease BTW) although I've no idea if it's split screen or not. I have the 1v1 Virtual On XBLA version which is online or system link MP only
Anarchy Reigns PS360 online MP had 2Vs2, plus 4 free for all and a 3 player horde mode (has a brawler football / rocket league like mode which might work with 2v2), dunno if the servers run anymore though.