Does it still work for you? I assume you’re using your iPhone as an audio device.
I had set this up a while ago, but my cell phone plan wasn’t fast enough to stream audio from my home network to my iPhone. Now I have a 5G plan and want to try again… but Roon isn’t showing the iPhone as an available output.
iPhone does connect to Roon via Tailscale though, and shows the 100.x.x.x Tailscale IP. Interestingly, in setup there’s a “Subnet for Linn streaming” option that also has a 100.x.x.x option (and it’s pre-selected).
But so far I’m not having any luck getting the iPhone to show up as an audio device over Tailscale anymore (and I definitely did in the past). It does show up when I connect to the same network though.