Hi Dan
I did the trip this spring, off season, one bus a day leaving around 1630 or 1700 from the bus station in Burgos. There is a stop on the street but I couldn't find it! The ride is about an hour and hour and a half depending on the number of passengers. It is a rural route, a smaller than expected bus and may stop at any crossroads, village, or cowbarn along the way, the driver and everyone on board are well acquainted. You will arrive in time to find a room and run to the church to hear them singing at vespers. The return trip leaves early say 0730 - 0800 so plan two nights if you want to see the monastery (you do!) and enjoy the little village. Accomodation? The main road is dotted with little pensions, nothing to write home about, right at the entrance to the village over on the right hand side is a structure marked “albergue”, from the outside, the place was not tempting. The singing is divine.