Dutchbird never owned V-Bird, as suggested V-Bird operated under the Dutchbird AOC. This agreement has now ended, and V-Bird operates under it's own AOC now, and the callsign is indeed 'VEE BEE.'
This construction has been used before, relatively often I understand. If I remember correctly easyJet started operating under another company's AOC before getting their own. Can anyone confirm or deny this?