Theme park tickets have nothing to do with being on the reservation. You can get a KTTW without a park ticket on it, if you are on the reservation (of course you can't get into a park without a ticket, which can be separate, charged and added to the KTTW @ Guest Services or the resort front desk, or transferred from a separate physical ticket onto a KTTW (assuming that it is either an unused ticket or is in the name of the person with the KTTW).
-steve