The owners should be the first to benefit from it definitely. Because if the gamblers, then, we will soon see the collapse of online gambling. Why? Because casinos will be bankrupt owed to AI used by gamblers. And I don't think before we reach that stage, casinos already found a way how to combat such potential threat.
Obviously, AI's use will be regulated. It won't be permitted to cheat the house and allow gamblers to get away with it. Instead, it will serve as an advisor that will help guide gamblers towards minimizing mistakes as much as possible. It will do wonders for newbies. Especially in games like Poker, and Blackjack.
As for casinos, I believe they will make use of AI to help detect cheaters and even provide real-time support for gamblers. Perhaps, there will be no need for someone to manage the house's bankroll as AI will take care of everything. And don't get me started on Quantum Computing. That will also have profound effects over the online gambling industry. But that's another subject. Let's worry about AI for now.