Hello, dear community!

I've very much enjoyed the 1 month with RIFT I've got from the raptr promo, basically getting me the game and the collector's edition upgrade. (thus 1 month playtime)
As I would like to buy some new playtime soon I'm asking myself if I should wait and see if RIFT gets discounted on the Steam Summer Sale, as the Steam version includes a 1 months subscription according to it's description.
But what confuses me is that the Notice there says that the subscription will only be included for new accounts. So I would like to know if buying the game on Steam will be equal to buying a 1 month game card, with the bonus of having the game on Steam, or if the game time will just vanish for my account and the only thing I get is the steam-bound client version?

In hope that someone can answer that.Thanks.