I am not getting a team bonus for any of my trades. Can someone help?

Assuming you're not a different team colour to your trade partner I'm guessing you changed team colour after you accepted the trade? If so you need to resubmit it, then once accepted, the team bonus will be applied.

I've got same problem actually, both nations (including mine) black team but no bonus.

:s

If one of you changed to black after the trade was accepted it won't work. Cancel and re-submit it.

As above. Its fixed by re-submitting the trade.