I should have been more specific when I mentioned water temps being warm. I meant warm for the range of bonefish. Now, this isn't too much of a problem over most of the Bahamas, which is several hundred miles to the north of the Caribbean basin proper - where water temps can reach high eighties consistently, especially in the summer months. Same for Central America.
I recall a story a fly shop friend of mine just told. A sport was heading south to Mexico for bones and had bought the usual arsinal of Charlies, Gotchas, Clousers, et cetera. My friend said he should take some Vaverka's Mantis Shrimps on #8 hooks, which met with some resistance. This is not a very well known flats pattern, but I turned my buddy onto it a few years ago on a trip to Ascension Bay by using a variation of that fly I've dubbed The Usual (homage to how many fish it's taken for me). It's subtle coloration and lack of flash really gets fish going... even picky ones. Anyways, turns out that fly was the only one that caught fish during what turned out to be a particularly hot spell on the flats. By the end of the week they were cannabalizing other flies to make Frankenstein versions of that fly.
My fly shop buddy happened to be the one that turned me onto this notion of water temps effecting fish. He was adamant with the sport that the warmer water on the flats would require neutral flies that had a lot of presence in the water even when hardly moved at all. I never put it together like that but do recognize the overwhelming success of flies like that and smaller Merkins tied with no flash. Given these two flies in various weights, I'd feel confident on the flats from the Keys to Hawaii to Honduras.
Of course, given an oceanside flat with fresh water on a rising tide, I'd fish a Gotcha in a heartbeat or a small, flashy Turd that barely makes a 'plip' as it lands in a school of tailers. These fish fresh from the cooler water would be more aggressive and want a little more stimulation - more flash, faster strips, et cetera.