There is one real SFOS/Aurora banking app from VTB bank (It is a large bank under all imaginable EU suxxions). Another true Russian banking app is SBPay (payment service from the Russian national card processing center. Similar to GooglePay or ApplePay). It is supposed to be rolled out soon. Source 1 Source 2. Other banks still provide only webviews of their online pages. The difference is that there is some assurance that they work, while the same servers would not function under SFOS browser.
The largest bank in Russia Sberbank issued a public statement that they were going to create an official app for SFOS years ago, but they did nothing. The press release was revoked after my formal inquiry as a client about the state of development. Now Sber is a founding member of a consortium that declared creation of another mobile OS based on AOSP - StarOS. There are smartTVs and smart speakers from Sber in any large Russian electronics shop.