If you add a pair of Ones as surrounds to the Beam, when you play the line-in audio from the Port, it will play to both the Beam AND Ones at the same time. If you want to play the line-in audio to only the pair of Ones, they must be removed from the Beam as surrounds first in the Sonos app.

Thanks GS, and with the Ones I can avoid delay in sound watching the tv, is that right?

If the Ones are bonded to the Beam as surrounds, they will play the surround channels from the audio source and have no delay. But if you group the Ones with the Beam, you will probably experience a delay from the Ones when playing TV audio.

Thanks again. Can i determine through the app whether speakers are bonded or grouped?

But more broadly, if I have a tv, turntable and cd player together how can i hear all thru sonos without having several speakers doing diff things, and withiut tv delay? Generallly the speakers that seem to go with cd/turntable (era, five) also come with tv delay, it seems.

To add (bond) speakers as surrounds, follow these instructions:

https://support.sonos.com/en-us/article/add-surround-speakers-to-a-sonos-home-theater

To group speakers, follow these instructions:

https://support.sonos.com/en-us/article/group-and-ungroup-rooms

The best solution is to add (bond) the Ones as surrounds to the Beam. This will create a 5.0 home theater setup. When you play the line-in audio from the Port, the music will play in sync out of the Beam and Ones.
 

TIP: Set the Music Playback setting to FULL under the Surround Audio settings in the Sonos app to get full stereo playback out of both the Beam and Ones when playing music.