Passport in Apple Wallet

Currently, only Arizona, Colorado, Georgia and Maryland support adding driving licenses to Wallet.

Add your driver's license or state ID to Apple Wallet - Apple Support

Apple has not, to the best of my knowledge, said anything about passports.

If all you want is the image, you can always “Scan a Document” into a Note. (This is actually a fairly wise practice in case your license or passport is lost)

As far as a “mobile passport” being accepted in significant areas of the World; I’m not holding my own breath waiting.

Not yet! But rumors guess that there will be a function like this in the future!