how phantom components get commit location when branch is committing to WC location in MFG constants

we've chosen Commit to WC location as Backflush option in Mfg constants. Mfg. Item has Routing with one step. WC is setup with location XXX. Routing has override location YYY. BOM for this item contains phantoms. Those phantoms have components. Work order is cut and phantom component items are placed on the parts list for the mfg. item. Which consuming location will be assigned to those phantom components? The WC location, XXX, the location on the Mfg item's routing, YYY or some other location like the component's primary?

Thanks,

Mark