how to connect my wife's iPhone with our Home mini pods

I set up one of my mini pods with my iPhone and now am trying to also get the pod in my wife's iPhone HOME.

No go.

I have two iPhones (wife and mine both 14 and up to date). I have two pods, one downstairs (set up with my iPhone) and one I will set upstairs.

I want both iPhones to be able to use the intercom, play music from playlists and use them as speakers when answering/making phone calls.

????????