Not familiar with this Yamaha, but if it has a line level input, you’d want to attach a Sonos Port to get the signal from Sonos into it. They won’t talk via WiFi. 

Thank you for your reply Bruce.  I'll look into the Port.  You would think playing Pandora out of the same account would sync up not matter what device started it.

I’ve found that not to be the case for internet streaming. I’ve often used multiple streams, in the most recent case from iHeart radio, and there is often a slight delay on one stream versus the other. Not sure whether to attribute that to a server issue, a network path issue, or what. In most cases, I resolve that on my Sonos by simply grouping rooms. But if I’m using, for instance, a phone and the streamers app in one place (headphones), and the Sonos connection and speaker somewhere else, there is often a slight difference between the two. And I’ve seen the same thing on two TV sets, connected to the same DirecTV account, tuned to the same channel. There just isn’t any effort made to sync Internet streams, in my opinion. 

It's not a delay, it's completely different songs from the same station.

Well, that certainly suggests a differing connection, and no attempt whatsoever to even recognize the account connection. You may want to ask Pandora about that.