If it is a hen I'd be very worried about injury from the cockerel. I have heard leg or hip injuries reported several times. In my experience bantams are so fast, if they have plenty of escape routes and perches, nothing can get near them. Our little Leghorn hens used to escape on occasion and snatch food from under the beaks of the Orpington.
We took in some Pekin bantam cockerels which had been dumped on some local waste ground. They were so nasty that they ruled over the large fowl (and were despatched ultimately when they went for me).