Bondmaid is simply nothing more than the Torvaldsland word for "slave". Whether a particular bondmaid is a hot slut or not depends on the girl, her training, experiences and owners. Just as there are southern tower slaves who serve FW there are also bondmaids who serve the FW of Torvaldsland. If a FW of Torvaldsland has the means and inclination to own slaves she can if she wishes buy them and if she wants them to act unsexual she can require that. If so she'd be wise to buy girls who haven't been long in the hands of men!
When Tarl and Ivar go to kidnap Hilda the Haughty we learn that she owns no less than five bondmaids, who sleep in the room outside her own.
I looked up. I could see the window of the quarters of Hilda the Haughty, daughter of Thorgard of Scagnar. There was a lamp lit still in the room. Apparently she stayed up late. Outside the door of the compartment of her five bond-maids, curled sleeping on the floor, on their straw-filled mats, chained by their ankles, which area led into her own apartment, somnolent and bored, were four guards.