no follow in battleground since 5.2, I buy a 2-seat vehicle in Dalaran , once mounted, 2 toon can be seated together.

Main toon:
Press the macro to eject npc

/run i1=UnitInVehicle("toon1");i2=UnitInVehicle("toon2" );if(i1==nil) then EjectPassengerFromSeat(1) end;if(i2==nil) then EjectPassengerFromSeat(2) end;

toon1:
IWT with main

toon2:
IWT with main

Hope it's useful for you.