You’re wanting Google speakers and Sonos speakers to play in sync?  It’s not likely to happen any time soon. Sonos and Google use different patented protocols with different features for multiroom audio.  Same goes for Amazon Alexa.  It’s just a technical challenge, but a legal and business challenge as well.

Thanks for your response. I just assumed it would work bc other products I have (for example Lenovo clock) which aren’t made by google are able to be grouped. Spent lots of time on the phone with both google and Sonos and both say they are going to work on it...who knows. 

But a Lenovo clock is just a speaker.  Sonos is a multiroom synched audio system in its own right.  I would be extremely sceptical that you spoke to anyone sufficiently senior at Google or Sonos for there to be any credibility in the claim they are working on this.  It would be highly commercially sensitive, and there has been no official word to the best of my knowledge.  I think it is highly unlikely this is something Sonos would want to do.