No, the Playbar doesn't support Dolby Atmos - you'll have to go to the new Sonos Arc; it's Dolby Atmos capable, but only if you have a new TV with an HDMI eArc connection.

Only with this HDMI eArc connection do you have uncompressed Dolby Atmos on the Sonos Arc. You can also connect the Sonos Arc to an "old" TV without HDMI eArc or HDMI ARC connection to the Toslink connection using an optical cable adapter (included with the Sonos Arc). But then you will only be able to have Dolbi Digital; Atmos is only possible with eArc or, with certain new TV models, with HDMI Arc.

With the Sonos Arc, the TV is the important interface, because the Arc has only one HDMI connection and it must be connected to the TV and the TV must be able to pass the signal.

And the Sonos Arc requires the new Sonos S2 app - if you still have older devices that are not supported by S2, then you have a problem here, because older devices cannot be combined with new and Sonos S2-capable devices.