When we were there earlier this year, we did see a sign clearly stating no motorhomes past a certain point, which was just before entering the hedged parking bays.
However M/H's were parked inside this area, so we did similar.
Later that day, the Guarda came around and told us all to move, to the more open area (where you first drive in) or face a fine.
I think you may find, it is not an official aire, but gets tolerated to a certain point.
The borne is on the main road!
Tramping the Dream, Enjoying the Pot of Sunshine at the Rainbow end!