500k total no win bonus. Champions with PPV points don't get (need) win bonus. Remember he will likely get a couple of millions over that in PPV points. Forget his brothers, Jon makes nearly as much as their yearly salary in ONE night. He doesn't need to travel around the US on a daily basis, he just fights twice or 3 times a year and makes millions each time.
In the end, he spends 100X less time in front of a live camera yet he's paid tenfold for the camera time. Think about it: minus the promotion and the few interviews, Jon spends 25 minutes in front of a camera to earn millions (2M/3.5M I would guess after PPV points). To get the same amount, his brothers need to spend countless "game hours", never miss a game, never miss practice and follow the team everywhere while attending each post game interview every time.
I don't know how much his brother really make, their only advantage is the union representing them and the team they're playing for. In the end, they both are just football players among other. None of his brothers is the superstar of his team. Jon Jones is the LHW champion of the world, one of the 3 most prominent UFC fighter and likely the one getting the fattest pay check (although we don't really know the total after PPV points).