From the way SE described it, you get the reward(s) when SE gets your subscription payment. It doesn't include 30 days or the purchase price. If your first subscription payment is due on September 27, when you'll get your reward once SE's billing system has received the payment. If you chose to bill every 90 days, SE will bill all 3 months on the 27th and if successful, give you the 30, 60 and 90 day rewards.

So yeah, people who applied both platforms to 1 account get 60 days free and won't see the rewards until then. And v1 people who only get 14 free days will be getting their rewards on/around September 10.

At least that's how it sounded to me, from the LIVE Letter #8 (Reinheart's translation), and SE's posted info.