There is a wall bracket, if that’s what you mean? Check under Accessories on the Sonos website. 

No not a wall bracket. My tv extends away from the wall, so looking for a mount to connect the arc ultra under the tv. 
 

any recommendations please?

It depends on what you mean..
There is a wall mount for it.

If you mean like mine where my TV can be pulled out from the wall and rotated then there is also a part that can be mounted on the bracket you already have.

Thanks Peter. Yes like yours in the second photo. Is that using the arc ultra wall mount, or did you buy something different?

I have this bracket for my TV: TVM 5855

Bought this to mount my Ultra under the TV: SOUND 3550

thank you Peter