Just a few quick points. Once you have metered the subject for the strobes and adjusted the strobes (distance or power or modifiers) to get the desired fstop, the background will be exposed by the strobes hitting it (if any) and the ambient light. Additional strobe light may be placed on the background which will also change the mix.
In general when the background is lit by ambient light and the subject by flash, and you want both properly exposed, you set the fstop for the subject and then you meter the background using that fstop and asking your meter what shutter speed do I need at that fstop for a good exposure. That's what you set the shutter speed to.
Re: Behind the Scenes Photo Shoot, Las Vegas Mag (P, M)
Cheers,
rfs