"I am not sure if Sun Cruz comes under US law since they operate out of the country."

If they operate the casino like Carnival does, US laws apply to the casino even when they are operating in international waters. I hit a progressive jackpot on a video poker machine while on a cruise to the Bahamas a couple years ago, and the casino manager insisted I take a W2G, whether I wanted it or not! If I wasn't a US citizen, I wouldn't have gotten a W2G.