Any resources that have not been collected will still be in the Gold Mines, Elixir Collectors or Dark Elixir Pumps. The protection level of these buildings is very low. Meanwhile, war win bonuses (until collected and transferred to storages) are stored in the Clan Castle, where the protection level is very high.
When collected, resources are moved to storage buildings and the Town Hall. Town Halls hold an equal share of Elixir/Gold along with storages, whereas a flat 20% of all collected DE is deposited in the Town Hall. The protection level of these buildings is high. Town Halls hold roughly the same amount of lootable Gold/Elixir as one storage, and 25% of lootable Dark Elixir.
If no resources have been collected and the storages are empty, you may even attack a storage or Town Hall without scoring any loot. Also, remember that you don’t receive loot from a Town Hall or Clan Castle unless it’s completely destroyed.
Storage and Town Hall Protection Levels depend on your TH level relative to your opponent’s. If you attack a lower TH player, the loot you stand to gain is less than when you attack someone at your level. Attack someone above your TH league, and the rewards can be even greater.