Yes, you can play music on an apple watch without the phone. You need to download your playlist or album in the Music app. There is no headphone jack for Apple Watch, so it should work with Bluetooth headphones as well. The speaker might not be super loud but will do the trick if you are alone at home or maybe waiting somewhere else where there isn't loud noise around you. Otherwise, it does have a microphone which means that Siri works too! Enjoy all these features of Spotify on Apple Watch now! Don't forget to update your iPhone and then go into settings -> general -> about activating Bluetooth too because otherwise, it won't work either way!!