A dream is a dream, that's it. Although in some people's dreams, they might find a hint tips on what they should do in reality, it's not the case that mostly happened to everyone. Instead, it will just create a false expectation especially if that doesn't happen in reality.
What I see in the situation is, that if the person is expecting too much in gambling, that mindset creates the dream related to gambling.
Generally, I do not take dreams serious because many awkward things have happened over numerous dreams people had in the past which has never have anything to do with their real life and so on. Besides, many dreams do not really last long in the memory since it is something done unconciously - in a state of mind that one does not introspect. How do you then bring such things to your real life and how does that prophetize the gambling you do in your game?
I see dreams as fictions generally and that's how I also take any story that is drawn from it. Although one would not outrightly neglect dreams per say, but in general terms, I see dreams as fictions and do not really have anything to do with your real life.