So, this has also happened to me over the weekend:
I had my brakes bled at an auto shop on Thursday. Later, over the course of several 5-mile drives and several days, the brakes have gone from "totally fine" to "pump and pray."
This shop is not a VW specific shop, and it was my first time there, AND they left a &@#$%& box-end wrench in my engine bay... I don't trust them, is what I'm saying.
Anyway, is there anything the mechanic could have done when bleeding the brakes to have upset the system? Assuming no leaks (I haven't found any), do B4 master cylinders tend to just crap out after a fluid flush?