Given the limited amount of tournement players the bonus for having trading partners of the right team colour should be eliminated. Maybe substitute a happiness bonus for having 5 full slots regartdless of bonus resources. Winning has a lot do do with winning the the resources "lottery". If you get a good set and full trades on day 1 you have a distinct advantage.

I like this idea. Team bonuses aren't based on five, so the replacement shouldn't be either. Maybe something based on the length of time you've had the trade for.
New thought. Not having team bonuses kind of defeats the point of teams. You could still be sanctioned by team senators, but you could easily avoid that by not trading on your team. And you'd still get the same bonus.