Yes, Surround Sound works on Apple TV 4K. This streaming device automatically plays the highest quality of sound that’s supported by your entertainment setup and the content that you’re playing. When your Apple TV 4K runs on the latest version of tvOS, you can enjoy movies and TV shows in Dolby Atmos. To play sound in Surround Sound or Dolby Atmos on your Apple TV, you can go for one of the following setups.
A TV with Dolby Atmos support
A Dolby Atmos-compatible soundbar with a Dolby Atmos-compatible TV.
An AV receiver with Dolby Atmos support.