QFT, Boca Grande is popular because it was just how things worked out for the TV coverage and other variables. There were even caught around the east coast of Boca Raton when I was down there a while back. Plenty of equal spots compared to Boca Grande around the state. Just gotta find out their migration patterns.Plenty of great spots for Tarpon all throughout Florida. Seasons change the bite in different locations of course, but there are a ton of good spots that are a lot less crowded. The backwaters of Port Charlotte offer great Tarpon fishing and a greater range in the size of the fish to be expected. The spring bite along the beaches outside Tampa Bay from Anna Maria Island North to Dunedin are also highly touted. I don't have enough experience fishing for them throughout the year in those areas so I can't really suggest the best times overall.
Of course there is always the Florida keys. This is my favorite place to fish for them. You can catch them nearly year round, from 10lbs to 200lbs, in canals 6ft wide to open ocean-side flats and on dead, nasty baits to fly tackle. This is where I started Tarpon fishing on family vacations years ago and its still one of the prettiest places to fish for them in the country.