You can create two Zones; one will be used for the playlists, the other for everything else.
If you only have a few playlists, you can list those individually in the rules. More than that, it will be simpler if all the playlists were in a single playlist group.
The rule will be easiest to create in the Search's Wizard mode (Ctrl-Shift-F). Under Rules, pulldown Playslists and select is any and select the one or more playlists, or playlist groups, that you want to use. Select Import/Export and copy the entire expression.
The, go do the ZoneSwitch rules, Enable ZoneSwitch, define the zone and edit the rule to be:
[=paste here what you copied earlier]=1
and select the zone to use (and also disable playback in other zones as desired).
Your second zone will have no rule - it will just play everything else, since it is the second (e.g. a fallback) rule.