Hi Malduncan and welcome to the site
I have 2 bantam cockerels with separate runs and groups of girls. Mine are very friendly, but having an aggressive bird can be difficult. If he sees you as the enemy, the hens will keep their distance, as he will discipline them if they get too close to you.
The usual advice in these circumstances is to cull the bird. It is a hard decision to make, but if he's causing so much trouble, you should have a good think about whether you do want him around. More hens are not likely to tame him and if he is known to be aggressive, re-homing isn't really an option.
The lack of eggs could be due to your rescue hens getting older. Hens are replaced in a commercial egg production system as soon as their egg laying starts to tail off. The bantam will be a more seasonal layer anyway, peaking in spring. Hens usually moult over summer as well and that stops them laying.
Hope this helps a bit