Does the temperature of a tennis ball affect how high it bounces

Yes, this is because the gas molecules inside the ball expand as temperature increases, so the gas molecules expand, their energy increases and they bounce around faster inside the ball. That's why higher pressure leads to a higher bounce of the ball. Likewise, a lower temperature will lead to a lower bounce.

Yes, the colder the rubber the less it will bounce because the cold is making the rubber act as if it is frozen in a way.