Ensure that the Pass has been added to the user's Passbook (or other mobile wallet app).
The location feature is used to help a pass holder find a pass when they are most likely to need it. When they are near to a specific location an alert is displayed on the lock screen. If location services have been disabled on their device then they will not receive this type of alert.
When the pass is displayed on the lock screen is also dependent on the type of pass that is installed.