@PARA45
I see your point but I don't think it's specifically a senior citizen discount.
In Australia if you have a seniors card it might give you subsidised travel or club membership, seniors meals at same club. Seniors group tours travel is probably not discounted but more a package to meet market requirements and tailored to a budget friendly itinerary.
I'm sure outfitters here can tailor a package and name it what you like but don't expect the royal service when you tailor a cheaper package.
Can always ask for quotes and see what you can negotiate.