Your itinerary so far looks very good. May I suggest the following:
Belorado - Villafranca Montes del Oca: Albergue/hotel San Antonio Abad: Tlf: 947 582 150. The municipal albergue has been closed for some years now. Food, good facilities & bar there. Good.
Villafranca - Ages: Albergue La Taberna de Ages. Good food reported. Tlf: 947 400 697/660 044 575. San Juan de Ortega has had mixed reports over the years, and it is nothing there except the albergue. Ages is just a couple of kms further, and is a
very nice little village. When you come to Atapuerca next morning, you can visit the museum of the first Europens, if you like. Plenty of time before Burgos.
Ages - Burgos: Easy day. But beware: Be sure to walk the River route! If not, you'll have to walk some 8 kms in an industrial/suburb area on asphalt! Tip: After the height where you see Burgos, keep left. Directly after crossing a bridge over a highway, take left into the village of Castanares (some distance away, along the fence surrounding the airport), where you will find the river route. For a full/detailed description, I have placed
a link for you here. That post also contains PDF style maps, links & instructions that will help you greatly.
You can also use the Search function on this forum, in the upper right corner, and search for "river route". More info.
I also would recommend the albergue Quatro Cantones in Belorado. They have a pool
The ordinary route into Burgos is probably the worst of all days on the CF, far worse than out of Leon, so it should be avoided at all cost. Instead, enjoy a beer/lunch in Castanares, and then enjoy a peaceful walk along the river into Burgos. A perfect day!
Buen Camino!