Internet + Mobile Savings is only applicable to paid plans. If you are receiving 12 months of free 1GB service, you will not receive additional mobile or Internet savings. Once your promotional period has ended, you can start receiving additional savings on both your Internet and Mobile services.
If you have other lines on your account (any previously added 1GB lines or any 3GB or Unlimited lines), those lines will receive the appropriate level of Internet + Mobile Savings on each mobile line and on your Internet account.