I have mounted these LED lights (and the filiment lights before the LED) holders (which seems to be some type of synthetic material) on the bow of both Hypalon and PVC inflatables. I have always used the single part adhesive which is carried by West Marine. (for PVC or Hypalon--separate adhesives). I would use the specific glue. 5200 will work, but it can be messy. In fact I once repaired a PVC boat with 5200 where none of the other glues would work. I try and find some other "D" rings to put on the boat when I have the glue--such as for tying in seats, fuel cans, or protective covers for the bow.
Some water cops are very strict about having these lights on inflatables or other dinghies...and the lights are cheaper than the fine. A few years ago Pensacola Yacht Club had a cruise to a members house, up a relitatively remote bayou--and just as the party was breaking up, the Alabama Marine patrol arrived in force and ticketed every boat which did not have full legal running lights.--I belive that they got over 30 dinghies.
At that time my dinghy was a 12 foot aluminum skiff, with a battery and running lights, so I was "safe"...