Passbook has nothing to do with Maps. The location-based lock-screen notifications are based on geographical coordinates (longitude and latitude). See here under "Relevance Information".One possibility for the location based stuff to not work is if Passbook is utilizing the craptastic Maps app. In the US, at least where I live in a major metro, many POIs are either missing or pinned to the wrong location, so the app may not know that you are at the store based on your location (expects you to be in the ditch a couple blocks south for it to pop up, perhaps)