Adding a hitch to the rear of your TT will work just fine. I know several people who have done it with success. As stated above, make sure you find a quality welding shop in your area to do the work.
On a side note, why not install a front mount receiver on your TV and carry the bikes out front? I just ordered one from etrailer.com and a Swagman 3-bike carrier from ebay. I didn't want to take any more weight off of the tongue of my TT and want to free up some space in the bed of my truck. That's why I went that route.
Either direction you choose will work beautifully.
Dave and Amy
5 kids...2 with 2 legs, 3 with 4 legs
2008 Jayco Jay Flight G2 29FBS "No Worries"...traded in on a...
2016 Palomino Columbus 385BH "No Worries II"
2011 F-250 Super Duty Lariat, 6.7L PSD "The Mistress"
B&W Companion slider