For WDW, I would recommend using frequent flyer miles to get there. Then, use SPG or HHonors to stay at one of the on-property hotels. If going to DisneyLAND, I would recommend using miles to fly and HHonors or SPG to book the cheapest hotel possible - points-wise. Often, this is Hampton Inn for 12,500 HHonors points/night. Sure, you will be 20 miles from Disneyland, but if rental car, gas, parking, and Disney passes are your only expenses - outside of food/souvenirs, you're getting off WAY cheap.

If you're making even 2 trips to Disneyland, the annual pass may be worth it. If you're making 3 trips between WDW & Disneyland, Premier Pass typically is worth it. Trading miles for passes does not tend to offer a good exchange rate, but as DavidAL insinuated, a case can be made that it is better to spend miles/points now and dollars later.