Hello suresh_bhat
Welcome to the SBB Community.
It is either way.
You can purchase tickets using one and the same account. Then, both of you can download the app and use the same account. All tickets and travel cards will show up on both phones, simulteanously. The same account can be used on three different devices.
From a user perspective, having everything on one phone / in one app is handy. But you will always have to show 4 QR-codes (2 SHFC + 2 tickets) and swipe forth and back while the inspector scans your tickets.
From a ticket inspector’s perspective, having everyone their own ticket on their phone is handy and less time consuming rather than if all tickets were on one phone. This can become very cumbersome with larger groups.
Important is, create an account on www.sbb.ch > login (no customer number) BEFORE purchasing anything. Make sure you are authenticated with your account everytime you purchase a ticket. You can well do so through the SBB Mobile app.
There is no need to use the Apple wallet. If you had purchased the Swiss Half Fare Care with a customer account, it will appear in the SBB Mobie app as a ticket.
And, make sure you have your physical passport with you; e-tickets do require an official proof of identity, no photos of it, no photo copies.
Does that answer your question?
Kind regards,
Roland