just saw your post...
sorry I don't check in here often. Hope you get to see this post. there is plenty of excellent riding in Jackson Hole and several free or near free campsites(primative) that you may be able to park the VW in, in the jackson area. A ride up snow king mtn. (hagen trail) in the Cache Creek area would be your best bet in jackson. Other trails worth mentioning are putt-putt, black canyon(wilson,wy), game creek and shadow mtn.(free camping?)
Not much riding to speak of in yellowstone or teton NP, just a few service roads and such. For example you could ride your bike into the lonestar geyser area on broken pavement and the old faithful area has some bike trails. I believe you can ride a dirt road close to bunsen peak in yell, hide the bike and then check out the peak and osprey falls nearby. There is a very scenic ride along the snake river called the RKO road near jenny lake in grand teton NP, mostly just a dirt road, might see prong horn in there. Sorry for the late post hope you have fun. Let me know if you need any advice on yellowstone or Grand teton, like little known warm springs you can swim in and such.
