There may be a bit of issue with his trailer guys. The ALiner is not the same as every pop-up, or "tent trailer". Apparently many are known for having frames and rear bumpers too weak to support a bike rack. It depends on specific year/model information. Also the roof is not like a regular pop-up roof.

A rack has been added by some owners, just googled for "aliner bike rack" - there is plenty of discussion by Aliner owners.

What about a roof rack on the tow vehicle for the bikes?

I know nothing of folding bikes, so I can't answer the OP question.