I've taken the cab rides from various resorts to the WDW golf courses. Your resort will have the vouchers (not sure how this works at Fort Wilderness though!) and get a cab if there is not one already waiting. Best to check with a CM at the resort the night before to be sure.
BTW, the taxi voucher includes a generous tip for the cabbie, so it's all fast and easy. The Bonnett Creek Golf Club is where the Eagle Pines and Osprey Ridge courses are located, they are literally just up the road to the east of the main Fort Wilderness entrance. Osprey Ridge can be very tough on a windy day, but is very scenic and should be experienced
at least once.

Magnolia and Palm are where the Disney PGA event is held every October, over near the Poly and GF. Lake Buena Vista doesn't quite measure up to the other four, but is still very well maintained and is the cheapest, esp. at twilight rates. Magnolia and Palm will give you free range balls if you show up early. Osprey, Eagle Pines, and LBV will charge you.
Call "The Starter" at (407) WDW-GOLF up to 90 days in advance for tee times. Don't wait til the last minute, the tee sheets do fill up, esp. for morning rounds, since you are much more likely to have thunderstorms in the afternoons. And be sure to ask about the "Two-For-One" discount (or Florida resident pricing if he has a FL drivers license)! The Two-For-One pass includes two rounds for one golfer at any of the courses, so it costs the same to play the most expensive course (Osprey) two times as it does to, say play one round each at Palm and LBV. If you don't ask about these discounts, they won't tell you about them on the phone.
And tell your FIL to, "Hit 'em straight!"
