I'm not sure if this helps since I'm not sure how well 36 is going to work, but I was looking for a century route to ride and found one that included Terry Hershey and G. Bush as part of the route. Link: http://www.bikely.com/maps/bike-path/Ryans-century-ride

I was thinking that if in San Felipe you were to turn right off 1458 onto Park Road 38 (first intersection after bridge) follow it around to Peach St. then turn right at Peters San Felipe Road you could follow that to 36 take a right and on up to Bellville.

I haven't followed that route though, I don't know what the state of construction is on that route (I learned yesterday that the M.U.P. in Terry Hershey was closed at Beltway 8) or if 36 is even ridable at all (satellite photo is pretty fuzzy).