The 10% bonus is for Freedom card holders who also have a Chase checking account. You don't have to activate it, it's automatic. I suggest you visit your local branch and speak to a banker, they can explain it all to you, and review your profile to make sure you're activated for all the sweepstakes that are offered, your checking and credit cards are in the same profile, and you're getting all the other advantages.
Yes, I'm a banker for Chase, in case anyone's wondering. Good bankers will always try to save you money, so don't be afraid to go in and talk to one.