I didn't join a travel club, but have a Continental Airline charge card and charge EVERYTHING all month, from groceries to kids college tuition and pay the bill at the end of the month. (Well usually) Not only have we gone down to WDW with miles, but all the way to Hawaii as well.
There are black-out dates, but we've always been able to work around it. If if means being able to travel more, it's worth looking into.