At Google I/O 2017 the company announced Bluetooth streaming will be available on Google Home, so that you can stream audio from any device, not just those running a compatible app. Over the last day or so, Android Police reports that some users have received a software update to version 90387 that added an option for "Paired Bluetooth devices" in settings. Using Home for Cast-enabled apps is great, but Bluetooth support will make things more universal. So far the update does not appear to be widely available, and Google has not officially announced it but if you have a Home at home, take a look at the settings and see if you're among the early testers.