There were two facilities keeping this species when I lived in Queensland for the best part of 2007: David Fleay's down in the south and the Port Douglas Rainforest Sanctuary up in the far north, where I got to see this species. The CWSP does not, or at least did not, have them; in fact, when I was there, I don't recall a single native species, unusual for an Australian collection, although I think they were making a mixed macropod exhibit at the time.
Port Douglas also breeds them; in fact, they had just a few months before I was there and I caught a glimpse of the joey.
I believe that the animals at each park used to be housed together at a closed-access facility by the Queensland Park and Wildlife Service in Townsville for some experiment, but were later dispersed to the two zoos. How or why these two were chosen, I don't know though.
On a personal note, this exhibit looks almost idendical to the one in Port Douglas!