You're right Burgos is a whole different province. I just did a Google Maps search for a Burgos in Galicia, 'cause you never know, Spanish placenames tend to repeat themselves. But I couldn't find anything.
Also, "Santa María Galicia Burgos" would be a pretty odd name for a church. However, the cathedral in Burgos is called Santa María de Burgos. Where's your info coming from? Maybe one was from Galicia and another from Burgos, and somehow the cathedral in Burgos is involved in all of this.