Object parent Asset Bundle

Is there a way to know from which asset bundle object was instantiated?
Assume I’ve got web player project with world divided in scenes that are stored in bundles via BuildOptions.BuildAdditionalStreamedScenes. I load the scenes with WWW class and load them additive. Scenes are loaded when player approaches their world location. After scene loads the bundle is not needed anymore and I unload it along with corresponding WWW, _assetBundle.Unload(false) leaves already instantiated assets intact. Yet later I want to delete those instantiated objects.
I can mark those objects somehow, maybe tagging them or adding component with scene index, but it would be nicer if I could know from which bundle objects came from. Is there a way to do so? Or maybe I should use some other approach?

If I were you then I would write an “AssetBundleManager” class that takes a singleton strategy for managing classes that wrap each asset bundle. The class that wraps each asset bundle can keep a reference to objects instantiated, status of the bundle, etc.