Depends on what you mean by scene. Not much, really. As far as breweries go, there's one decent brewpub, Padre Island Brewing Co. Haven't been in a couple of years, and no beer I've ever tried from them was life changing, but it was not horrible. Restaurants usually have poor selection of beer. A Sam Adams Seasonal or the ocasional Karbach beer is usually what you'll find. The best restaurant for beer I've found is Gabriella's (several taps and bottles, sometimes with random gems). As far as beer selection in stores and supermarkets, HEB's in the area have come a long way in the last few years. There's one in Port Isabel with decent beers and always carrying a few canned options to take to the beach. Several of the Feldman's on the island are spotty, though some may have a couple of decent options. If you are looking for something a little more rare on the bottles, you need to go to the Feldman's Market in Brownsville (about a 40 min drive from the island). Or if you go to McAllen the Feldman's on 10th street will probably be your best bet. I just recently bought some BBH, and have gotten a couple of the St. Arnolds Bishop Barrel series there. For IPAs though, it is usually better to go to the HEBs. They tend to have more rotation and tend to be fresher.
Kelly's Pub had Bells Two Hearted, Left hand Milk Stout, and Karbach Love Street on tap among others about a month ago when I was there. Gabriellas has a handful of good beers on tap. There is an okay number of bottle options in some of the stores there in the island but check the bottle dates.
