I have made wrapped composite handles as well. I used jute twine, then brushed on a thick coat of slow-setting epoxy. The slower the better, it gives it more time to penetrate the cordage and to self-level. It's a good idea to mask off anywhere you don't want epoxy with tape, it's cheap and saves a lot of work later. I also turn it regularly until the epoxy sets up, so I don't have drips form. Once it's completely hardened, I sand it smooth and finish with a coat or two of spray-on satin spar varnish, masking again to prevent overspray issues. Masking tape is cheap and saves a lot of work!
I really like the way your handle turned out. I am in no way trying to criticize your work, just offering an alternative means to a similar end. Thanks for posting!
Looker