You will get 2.5gb+500mb for the autopay bonus so 3gb total. We were just worried that you may have thought you would qualify for the 2gb data bonus for new activations only.
The reason we suggest manually topping up your account so you have $35 in it to pay for the new plan is because there is a common glitch that happens when upgrading plans on autopay. Auto pay charges your card the old plan price that then fails to renew because you have insufficient funds and your service gets suspended. Manually topping up avoids that possible issue. The next renewal will occur normally.
Your rewards have a new account with the same login credentials as your self serve account. In your rewards account you will see "Join Public Points" avoid it like the plague.