Apple finally lists all the ways you can play audio on HomePod, and Bluetooth isn’t one
https://www.theverge.com/2018/2/2/16963722/apple-homepod-audio-sources-no-bluetooth-support
After a degree of confusion over the possible ways to play music on its new HomePod speaker, Apple has cleared things up by posting more information on compatible audio sources. The HomePod does indeed work with iTunes Match and purchased iTunes tracks as well as Apple Music, according to Apple’s website, which also mentions Beats 1, podcasts, and the ability to AirPlay “other content” from various Apple products. You should be able to beam songs from apps like Spotify, then, though you won't be able to play them with spoken commands.
This means no regular Bluetooth support — even though there's Bluetooth 5.0 connectivity inside the device — so Apple Music subscribers with Android phones are seemingly out of luck. In fact, the HomePod requires an Apple device capable of running iOS 11 for the setup process.