When you get a new level, an reward will be available, this reward has a validy of 2 years from the earning date, if applied or not. At the moment you need to keep tracks of the date when you received, since there is not a way to have it from the site.
Go to your account → Scroll down on the My Rewards Program box → Click on see details → Click on Manage my upgrades → A My Upgrades windows is open, clic on the bonus family mobile or internet → Select the upgrade and click on Apply
When the upgrades is applied, it will have Pending activation status and the bonus will be activated the next billing cycle.
When the new billing cycle will kick in, the bonus will have the status