I've had dreams where I was gambling, but I don't think in any of them that I had some epic win. In fact, I think I remember having a dream where I lost huge, like more money than I even had. And in the dream I was like, "Oh shit, F me." And then I woke up and had a good laugh.
I don't know if that's good or bad.
On a side note, I've also had an actual dream where I was the quarterback of the Dallas Cowboys and we won the Super Bowl thanks to my awesome play. I know that will never ever happen in real life, so maybe me having an epic gambling loss won't ever happen either since I had a dream about it. #fingerscrossed