Locking from the bathroom would allow a guest to prevent a host from accidentally entering the loo while its in use, but allow a guest to easily snoop in the hosts' bedroom.
@levisan Switch it!
@levisan You know those lock on 1 side, house internal door (bath or bedroom) knobs all have that small round hole centered on the non locking knob? Thats so you can stick a small metal rod or screwdriver in there to unlock it in an emergency (or if your kid decided to lock its bedroom or a guest passed out in the bathroom).
Hide a small rod (wire coat hanger piece held by 2 pin sized finishing nails) on top of the door frame so you can pop the locked knob from its "outside" side if needed.
@levisan add an occasional use only 2nd lock to the pocket door, bedroom side to lock it down whenever you plan on locking up the master bedroom.
@Klaatu that seems to be the consensus on the tweeter too