How far in advance can the Wildlife Discovery Excursion be booked?

[DLBDS]

How far in advance can the Wildlife Discovery Excursion be booked? This is not Wild By Design, Backstage Safari or the Sunrise Safari (which is for AKL CL only.). This is the tour provided to folks staying concierge at any Disney resort. Do you have to go through your resorts IPO or can you reserve it yourself? Thank Yoooooou!