In order for a package to be able to be used with an on demand resource the following must hold. Work through the following to resolve:
The on demand resource must have Bundles/Passes selected as an accepted Payment method. Edit the resource in On demand to check and update as needed.
The on demand resource must have the same tag as the relevant bundle/pass. You can check the set tag for the bundle/pass in Packages>click on package name from appropriate filter>review table in Details page. Edit the resource in On demand to check and update the tag as needed.
The bundle/pass must have on demand set as a purchasable object. Edit the bundle/pass from Packages>click on package name from appropriate filter>Edit this package to update as needed.