RE: The 1099 and W-2Gs were from the same casino, so I'm not sure why the proceeds are reported differently

@IRonMaN you have to loosen up and hit Jersey City or the Native American Land every now and then. 

Very possible but not conclusive answer: (Conclusive if given by Bob)

Casino 1099's could be related to promotional programs.  Cumulative jackpots (not from slots).  Poker hand incentives (quads beaten by straight flush), hitting X cards in blackjack without busting, hitting two royal flushes in a row in some table games, winning from quarterly drawings whereby you get a free ticket that goes to a big drum when you hit a black jack, things like that.  Every day, the casino add to the jackpot until no one hits it.  Once at at poker room, the "bad-beat" jackpot was over $100K...  I once beat Quad kings with a straight flush at Lake Tahoe, but the Jackpot was only for $3,000....  It would have been a  five figure amount in most card rooms.  Lake Tahoe poker business is very slow.  Do you want to see a picture of that hand?