marantz receiver

No... And yes. The Sonos speakers are powered, thus can't be wired to your Marantz. But your Marantz receiver with passive wired speakers can pair with the Sonos Connect, and be another room zone to the Sonos One(s)

Can' I use airplay 2 to connect, so do I need a sonos connect?

The Connect does not support Airplay 2, but the Sonos One does. You could use Airplay to the Sonos One, then in the Sonos app you could group the Connect and One together and the Airplay audio will also play through the Connect, and thus your Marantz receiver.

Actually, I believe your receiver itself is airplay 2 compatible. So yes, you should be able to stream audio from your iPhone/ipad to both the receiver and Sonos One at the same time.

Not sure if that's what you're getting at. Technically the receiver and Sonos One aren't connected in the scenario above. They're just streaming from the same source in sync.

thank you all, very helpful, what I would like is the marantz internet connection (radio stations) and apple tv3(connected to the marantz) to play via the sonos one, but not sure if that is possible?

I don't know if the apple tv can be an airplay 2 'source'. It can be an airplay 2 destination/speaker. Someone else with more Apple experience then me can answer this?

thank you, I hope so, cause the receiver is just a few months old, with wired speakers and heos which (wireless )speakers failed !, so I am very impressed with the sound the sonos speakers produce.