Hello Fiwoudau27
Tickets that were purchased as a guest do not show up in the personalised account later; you cannot add them manually.
Swiss Travel Passes are not available in the app, also not, when you bought as registered user. In fact, none of the tourist offers do. The SBB Mobile app only shows point-to-point tickets, day passes, and tickets as part of subscriptions.
Nometheless, you are welcome to show your Swiss Travel Pass on your phone as part of a PDF document; just keep in mind that you have to show your passport physically with your ticket (no passport copy, no photos of it). Also, a hardcopy of your Swiss Travel Passes is helpful in the event, when your phone is lacking battery.
Kind regards,
Roland