Thought I'd cracked the post-imaging ZCM bundle installs using the "zac bin" command but now found another hurdle

I've got two groups of machines I need to prepare differently, I can differentiate between them as they have different workgroup names. At first I assumed I'd be able to use this in ZCM to either define bundle requirements or make a Dynamic Group but it seems in either case I'm restricted to the default ZCM filters

Is there any way to add custom filters to the list e.g. WMI queries?