You'd do it more or less the same way, as you'd do it for full native apps.
Please have a look at the following pages:
The one and only difference between a full native application and JavaFXPort for Android is the User Interface (JavaFX instead of Android toolkit). The rest - the Bluetooth part obviously - is still written against the native API from the Android SDK. In contrast to iOS where you most likly would use som API from the RoboVM SDK (or if Gluon Charm provides something, you would use their abrstraction layer).
Hope that helps.
Cheers,
Daniel