On the iPhone this is already possible, the retailer needs to have a loyalty card in Apple Wallet and needs to have the pass be location aware.
This means when you double tap the home button to bring up Apple Pay you would also see the pass available.
For example the iTunes pass that you can load into Apple Wallet is location aware and should appear at the Lock Screen when you’re in an Apple Store. As well as being available from the Apple double click Apple Pay menu.
The only company is really using this feature are airlines for boarding passes they should automatically pop up on your arrival at the airport.