Dolby Atmos: does it do anything for two-channel reproduction?

You would use your current DAC for content that isn't atmos. For atmos content you would need a source (like apple tv, amazon fire tv/stick, x-box for streaming or a BRD player for discs). Then you would need either a HT processor or receiver.
I would only go through the above if you want an atmos immersive audio setup with at least a 5.1.2 speaker layout.

If you only want to listen to atmos in two channel use a headphone setup that is enabled with dolby atmos, much easier and also very nice:

https://www.dolby.com/experience/headphones/

For Atmos enjoyment you need an Atmos decoder.
When it comes to Apple Music, then there is a lot of confusion around it.
For one, using iPad or iPhone and Apple EarPods, you can listen to Atmos through Apple Spatial renderer - this will attempt to recreate spatial effect via 2 speakers only.

To really hear Atmos music from Apple Music as Atmos immersive audio (without Apple Spatial Renderer), you need to use appleTV and connect it to Atmos capable  processor/AVR/soundbar,

For detailed explanation see this article and especially section titled "5 - Apple's "Spatial Audio" Mess"

https://www.pro-tools-expert.com/production-expert-1/why-your-atmos-mix-will-sound-different-on-apple-music

Hi OP - I have a HT set up and that shares the space and some equipment with my 2 channel space.  Atmos via Apple or another streaming service isn’t designed to provide a benefit into a 2 channel set up.  As a previous poster mentions, it does make sense via headphone potentially but not in a 2 channel set up.  

I would only look into Atmos for music if you wanted a HT set up with a speaker configuration and equipment that supports Atmos.

For music listening I prefer my 2 channel set up vs Atmos via my Anthem MRX-1140 HT receiver driving my Atmos speakers.  I find Atmos via my HT set up to be a novelty, some songs can be really immersive but from a sound quality standpoint, 2 channel is far better, your mileage may vary.

Again, to recap - unless you want a HT Atmos set up, receiver / speakers there isn’t a benefit, point to adding a HT Receiver to decode Atmos.  Without the extra speakers, you won’t hear the intended differences from stereo recordings.   

Thank you all for the clarification about Atmos. I will stick with 2-channel, I guess.

From what I have read over the years, Dolby Atmos is the Successor of Q Sound and Sensura.

Q Sound succeeded Sensura, I am not aware of Albums being produced with the Sensura embedded, but the Q Sound has been used on both readily available CD and Vinyl on a limited number of Albums. The expansive Soundstage in all dimensions and the capability to conjure a sound/image anywhere within the soundstage is the strength of Q Sound.

I believe Atmos has the same capability, but do not know if it has been embedded into any commercially available Albums.