Thanks for replying to my question, I found that during the setup procedure for the Boosters there is a step, using the WPS feature, to make the WiFi Boosters take the same network name and password as the hub. (Before employing that step, the boosters have their own name and password).
This meant the camera connected to the booster network signal, and I am able to view its picture while connected to the Hub 3 signal.
Now I know it works, is it possible to add an additional remote WiFi Booster to the setup? i.e. have the one wired booster plugged into a power socket and connected to the router via Ethernet, and then have TWO remote WiFi boosters plugged in elsewhere?