Just came back from LHR on VS. I was connecting in LAX on my way to OAK.
The BP issued at LHR had "TSA Pre" only on the one relative to the LHR-LAX flight (therefore useless).
When I tried to use the LAX-OAK, which didn't have TSA Pre printed on it I was turned down.
Interestingly, at the SkyClub they reissued my BP and this one did say "TSA Pre" on it (useless again).