As far as I know there is no way to copy a composition + hosts (locations) from one Sketchup model to another, correct?
To copy a composition between models, you can export it via the Composition Manager window and then import it into your other model.
This will keep the parameters of your composition but you will need to select new surfaces as hosts since SketchUp entities are not part of the exported data.
Thanks Merwan, I thought that was the case. Looks like my landscaping changed anyway.