I'm pretty sure all the ones I have were bred in the captivity opposed to being caught. Bred in captivity I have no problem with - if you release them they have no survival skills. Being caught is taking them from one environment to another which is more than likely sub-par to what they're used to.
As for the dolphin being happy and living longer, that's great, and its well documented and proven that animals will live a lot longer in captivity than in the wild, regardless of the quality of life.
I just think that you shouldn't take something from the wild unless you are saving them from something or can provide a much better environment for them... Which, is unlikely to happen for dolphins