That's not a acceptable solution for us. I'd probably buy the whole bundle a second time, but I can't because the purchase is tied to the Apple ID and so I don't even have that option.
Two iPads using a single Apple ID, but with different Game Center accounts (two family members). iPad A originally purchases the Rise of the Runelords bundle, all unlocks visible, hoorah! iPad B restores purchases, bundle shows as "Owned" in the store (so "Buy" is greyed out) but cannot see or access any of the bundle material.