chess.com now accepts bitcoin payments to pay for membership
OP seems to be asking sites which allow people to play with each other for btc or in house currency which can be bought using bitcoins. Chess.com afaik doesn't allow any sort of betting.
And to answer your ques OP no I don't know any site which allows you to bet using bitcoins, the main concern like others suggested is it will get abused by cheaters using super fast engines like Houdini, Rybka, Swordfish, which players like you and me can't defeat.
They'd most probably develop bots so they can even use these engines to play for them in bullet/blitz tournaments because otherwise it will be difficult for them to copy paste the moves in time.
Yeah, any game can be exploited and likely will when there's money to be earned.
I think what may work, though, is a smart contract (basically, a contract between two people that's decentralized and has a contingency -- i.e., whoever wins). Or even have two people just escrow the funds and that person oversees a match somehow, paying out the winner (I'd take on this job, as this would be an interesting thing to watch).
I would NOT trust some automated site for something like this though.
In any case, I think the idea for betting on chess matches is a good one -- I just don't think it's viable (there wouldn't be enough play to make it worthwhile I don't think). It's more of a niche thing.
Has anybody tried this already? 
