TAAE1 & TAAE2 : how enable Bluetooth audio output

Bergerac

ON TAAE1.5.6 Bluetooth audio output does not work - at least in my app and in the provided TAAE-sample-app.
What is there to do?

my init-code is:

    _audioController = [[AEAudioController alloc] initWithAudioDescription:[AEAudioController nonInterleaved16BitStereoAudioDescription] inputEnabled:YES];
    _audioController.preferredBufferDuration = 0.005;
    _audioController.useMeasurementMode = YES;
    _audioController.enableBluetoothInput = YES;    // seems irrelevant to BT-output

How can I achieve Bluetooth output?
Does Bluetooth audio output work in TAAE2 ?

Thank you very much!
B.