The short answer is probably…

It will depend on your TV and what connections it has.  Ideally an HDMI eARC port but there are options for an HDMI ARC.  Another consideration is what are the sources of the Dolby Atmos - Internal to the TV, External, or both?

The best Atmos surround system, if your budget can stretch, is to use Era 300 as your surrounds.  These compliment the upward firing speakers within the Arc, with their own upward firing speakers, to give a more complete Atmos audio.

Hi, yea, my tv is new and has the eARC.

I have a beam gen 1 but considering buying a beam gen 2

Not willing to pay for Era 300s at this time, but understand I need a beam gen 2 or arc for Dolby Atmos. 

Just not sure if my sonos ones will pair with a beam gen 2 for Dolby Atmos? 

The Ones will bond with the Beam (gen 2). They will play surround channels because only the Era 300’s will do Atmos. In your proposed set up only the Beam will do Atmos.