Wolves winger Michael Kightly was brought down in the box by Clint Hill and Ebanks-Blake (pictured) sidefooted the spot-kick home with 17 minutes to go.
The visitors had adapted better to the swirling wind and driving rain in South London in the first half but could not find a way through.
Kightly came closest when he drove in a low cross-shot which was blocked on the goalline in unorthodox fashion by the heel of the diving Hill.
Wolves were poor in the second half and the game appeared to be heading for a draw before the spot-kick.
Reading went above Birmingham after coming from behind to win at Wednesday.