Are FaceID/passcode logins secure over public WiFi/hotspots?

Unfortunately, I find myself serving a 14d COVID-19 self-isolation period in a hotel which only offers unsecured public WiFi.

This has me wondering if all the financial apps on my iPhone with FaceID-enabled sign-ons are secure or not (e.g. Charles Schwab, American Express, etc.)

Can anyone comment on the typical security stack that would underly this category for app? Does everything boil down to a proper implementation of TLS access to the backend?

Is there any chance that using these Apps is still secure over public WiFi?