If you have a sky feed with a sky box you can run a cable to second site (bedroom) from RF2 feed from sky box and get a signal on your bedroom set that way
I don't think the second skybox will help without a second sky feed
If you buy a magic eye and a second remote you can switch channels on your sky set from the bedroom
I don't know what chance there is of getting a sky signal through your plugs but I guess it's unlikely
Alternatively if you don't like cables running round the flat and the walls aren't stone you may be able to get a signal via radio,see
www.satcure.co.uk