No! At least not directly! Beltpack transmitters deliver a kind of T-powering, a DC voltage between 1.5 and 9 V from their unbalanced input. This kind of powering works for many electret microphone capsules, for example in lapel-, headset- or instrument mics.
This kind of powering is NOT compatible with phantom power! Phantom power has a higher voltage (normally 48 V +/- 4 V) and works with balanced wiring only.
To connect, let´s say a gooseneck microphone to a pocket transmitter, we offer special versions of gooseneck mics like Classis GM 301.18 or Classis GM 305T, they can be plugged directly into an Opus beltpack without additional powering.