I have my rod holders installed or loose in a compartment.
That said if I wanted to mount them like you're planning to then 3M double sided tape is the first thing I'd try. "Scotch Mount Extreme" is one brand and I believe Gorilla makes one, too. Both should be available at Home Depot or Lowes or many other locations.
Simply clean both surfaces with an alcohol wipe or a clean towel and denatured alcohol first and you'll be amazed at how well it holds. It can be removed, too, without leaving residue. Just takes a razor to cut it off then it can be peeled away from the surfaces by rubbing off with your thumb.
I use it for a bunch of stuff including archery equipment. I've got a I-Troll unit mounted on my Ranger's dash and it's there to stay. The velcro mounting tape that came with the I-Troll lasted about the first hour I had the boat on the water.