question about tour buses and permits

This is puzzling me and so I thought I would ask if anyone could tell me the answer
Plus as it's Good Friday I can't contact the people concerned and I'm curious.

In our local paper there is an ad put in by a tour bus company. Amongst the many tours they offer is one that is : Gunbarrel Highway- Tanami Track - Oodnadatta Track. Nothing strange in that I know but this is the itinerary they give.

Coober Pedy, Aboriginal Communities, Tjala Arts Centre, Surveyor General's Corner, Giles Weather Station, Great Central Road, Empress Spring, Wiluna...etc

The part that has me puzzled is the bit from Coober Pedy to Great Central Road. Tjala Arts Centre is at Amata Aboriginal Community on the Mulga Park Road and I thought that it was not possible to get a permit to use this road unless you had excellent reasons. A tour bus does not seem to me to fit that criteria as surely it's no different to any of us who would like to travel this road.

This isn't a permits complaint letter at all. It's just that I don't understand how they can advertise a trip unless they know they're allowed out there and if they are allowed "how come"?

I don't think I'm misreading the itinerary as they are going to Surveyor General's Corner and they don't mention going via Ayers Rock or Docker River.

Viv