No, it is not possible to sync Sonos speakers with a non-Sonos device.
I am not sure if what you wish to do is supported by both manufacturers. It may have to be one or the other in this instance.
As much as I loved the AE and the Apple Airport Extremes, ( I wish Apple had continued in this arena) it may be time to go another route and use Sonos devices.
The Era 100/300 use Airplay 2, and so does the Port, which essentially does what the Airport Express does, and more.
You can use AirPlay to play a music source to both devices.
