If you sew the patch to a piece of similar rubbery material , you can use the adhesives for shoe repair ,
to glue it on, and not make holes in the bag itself.

or attach the patch, (decoration I Presume), with a Hot melt glue gun.

the white sticks are better than the clear, for that.

if the area is woven fabric, backed up by the separate Liner
then you can go around it with hand sewing too.