Generally, Wyndham resale points cannot be used to book WorldMark resorts directly. There is an exchange mechanism between the two systems, but only points purchased from the developer can be used in it.
Resorts with both "brands" are an exception. For example Austin has a single building that has both Wyndham and WorldMark units. You are still booking "Wyndham" units, but they aren't that much different---maybe marginally nicer, but not by much, and not always.