I would say this is an unusual way of betting because usually we talk about a fixed amount for either winner. It would appear that if the speaker wins, he gets $10 and that if the hearer wins, he gets $15; but I am not sure.
It's not the usual way I've heard it, either, but I would assume the same thing natkretep did. I'm more used to hearing something like "5 will get you 10", which in this case would be "10 will get you 15". That would mean "If you bet me $10 that I can't throw you and I can't, you win $15; if I throw you, I get $10."
Now that I write it out, though, it seems like it might be the other way around. The speaker is betting $10 against $15 that he can throw the other guy. If he throws him he gets $15. If he can't throw him he loses $10.