That dosent make sense. Your phone is just a remote. 

Are you using you phone as a hot spot for Sonos to connect to the internet?

Can you define what you mean by “Sonos cuts off’. Is this a complete stop to any audio playing or just audio interuptions?

What music service or audio source is being used when other household members experience this and are they grouping speakers when it happens?

Edit: you mention Spotify in your profile, are you playing Spotify on your mobile device away from home or do you have a Spotify Family plan with individual Spotify accounts added to Sonos?

OK to clarify- When I am connected to Spotify via the Sonos app playing music on my Sonos system, everything works fine. When I leave the House then the Sonos stops playing the music- Which makes sense because Spotify is coming with me.  
 

Now, when my wife is utilizing Spotify on sonos app on the Wi-Fi at the house and I’m at home everything seems to work.  But when I leave the house to go to the store And she stays home it seems to interrupt the Sonos/Spotify streaming

Spotify should only stop on Sonos if you are playing Spotify from the Spotify app on your mobile device away from home and you are only using one Spotify account.

​@RAF1000 

When you play music on the Spotify account within the Sonos app, the speaker(s) request that track from Spotify. What you then do with you phone should make no difference. You can smash it with a hammer and Spotify will continue to play because it’s the speakers requesting the music.

You leaving home makes no difference. 

It will only stop if:

• you’re casting from the Spotify app on your phone directly to the speaker. Clearly when you leave it can’t detect you any more. 
• (as ​@Mr. T mentioned) you start playing music on your Spotify app away from home and you have just one account (e.g. you might play it in the car). You will then cause a conflict back home because the speakers will be told that account is in use elsewhere. 

I pay for Spotify Premium and have used one of the slots to create an account called ‘Home Spotify’, using another email address, which I added to the Sonos app. This ensures that no matter who in my family is playing their own account elsewhere, the Home Spotify account is the one playing the music on the Sonos speakers...

 
- Does your wife have her own Spotify account?

- Is she using hers or yours when you’re at home?

 - What if she tries using Spotify, starting a stream when you’re already away from home?