You city would be what, exactly?
The number of locations with transport cards which can be loaded to Wallet is family small. If you follow the instructions in Add a transit card to Apple Wallet you will see that most of them are in China, with one in Hong Kong, two in Japan and three in the United States - where I suspect you might be located:
- Clipper (San Francisco)
- SmarTrip (Washington DC, Maryland and Virginia)
- TAP (Los Angeles)
Additionally, it's possible to use Apple Pay in other transport networks. See Where you can travel on public transport using Apple Pay.
*Just as an additional note: you can use a Clipper card lodged in the Wallet app in an iPhone on a Caltrain service to get to a station close to Apple Park - though you'd need a taxi to get to the visitor's centre from the train.