If you googlemaps 155 fisherton street, salisbury and look at where apollo blinds and takidir on the roundabout, you will see a yellow line opposite some parking bays with restrictions like those you mentioned.
The bays are also subject to those restrictions, even though the yellow lines are not in the bays themselves and double yellows stop prior to the bays.
As long as the sign you mentioned is on the same side as the bays, they are restricted. this is what caused the confusion in Salisbury, hence the added sign.
I wouldn't risk it, I agree it's confusing. Don't be surprised if you get ticketed. Why not use the Carpark down the street?