For cloth to cloth, flexible gluing, I would recommend "Barge Cement",
in a blue tube. I get mine from Ace hardware store; if they don't have
it in stock they can order it for you.

After I ordered some, my local Ace store now carries it on the shelf.
It's a bit pricey but it _is_ the stuff I use for such patches.

David Dewey

 [ "Barge All Purpose Toluene-Free Cement", in blue tube, Item Number
 [ DA071, Product Code V-4049.  The ingredients (methyl acetate plus
 [ solvents) are listed in the Material Safety Data Sheet (MSDS) at
 [ https://www.bargeadhesive.com/uploads/6/4/8/2/6482595/da071_da081.pdf 
 [ -- Robbie