Most agree, it is not a good idea to add a bike rack to the back of your trailer...to much bouncing around stresses the frame.
So that leaves:
1) between the trailer and tow vehicle
2) in the trailer or TV
3) on top of the TV
4) on top of the trailer (not practical - too high, nothing to attach to)
5) on the front of the TV
To date, we have taken our bikes either in the trailer or TV with "creative packing", but will probably be adding a rack to the front of our TV next spring.
There are lots of differnet ideas here on the forums, perform a search for bike rack
for some others.
Good luck with whatever you decide to do ~