I also could not register for this promotion online (said I was not eligible), so I wrote a quick email to RC Guest Services to check on this.
Got a reply back two days later to confirm my registration in the promo, but also noted that I was eligible to accumulate a maximum of ONE free night (not two nights, as stated in the T&C of the promo on the website).
So, is there more than one version of this promo where eligible members earn either a maximum of one or two free nights?