I'm using fWallet for Eurostar, plane tickets, etc anything with PkPass. Very minimalist, just does the job.

• code repository https://gitlab.com/TheOneWithTheBraid/f_wallet
• f-droid delivery https://f-droid.org/packages/business.braid.f_wallet/

As far as I remember, things other than credit/debit cards in Google Wallet are pretty much images that you can scan like you would a paper ticket. Maybe download that ticket somehow — if some other app provides the same android "activity" as Google Wallet (so it shows up in "Open WIth" menu when you clicj that button), you can use it to avoid Google completely. If it's hardcoded to use Google Wallet, make a separate account just for this ticket. Then just open the ticket in the app, take a screenshot, and use your favorite gallery app to scan it in at ticket gates.

You said you tried Apps from F-Droid, still FossWallet in F-Droid works good for me.

Do you trust any other provider? Amex used to have a payment type app but I'm not sure I'd call it a wallet. From what I remember Amex wasn't well used in Germany.

You're better of looking in the degoogle communities. Sorry, I still haven't learned to cite the communities here properly (there seem to be two forms). Type degoogle into a community search box (all one word, no hyphens)

I had a similar issue in my city. I had to talk to the human resources division at my organization, and they were able to work directly with the local transit agency to get me a physical card, but it was a pain, and it certainly wasn't advertised as possible anywhere. It may be worth trying to call people and ask.