How many weeks will it be before your bones stop getting sore after a tumbling class?

It's actually your muscles getting sore, not your bones, unless you are referring to your joints. It really depends on the person. But as you tumble more you will become stronger and more flexible and your body will produce less lactic acid which is the cause of your "sore bones" In short, your soreness will go away in 4-6 days tops :)