Hopefully you'll hear pros and cons from someone who has 'been there done that.'
Rear bumpers are not very strong and most bicycles on racks at the rear of a TT do lots of bouncing and twisting, multiplying the forces on the bike rack and the bumper. And, IIRC, many (most?) bicycle rack companies say not to use their product on the rear of RVs.
Hope you find out what you need to know.
Sherm & Terry w/rescue Eydie (min Schnauzer) & Charley (std Poodle)
2015 Jay Flight 27RLS, GY Endurance (E), Days: 102 '15, 90 '16, 80 '17, 161 '18
2006 Ford F350 PSD, 4WD, CC, LB, SRW, Cmpr. pkg, Equal-i-zer 4-p, Continental ContiTrac TR