My bears/phoenix bldgs no longer get NH because I have too many other bldgs that have way higher culture. The only way they would receive help would be from a player who actually loads my city and manually chooses the bldg to help. Those players are few and far between. Since the NH window chooses the building with the highest culture available, they never rise to the top of that list.
Here is the thread with the only notice I can find of when they removed the ability to use EE spells on bldgs that receive pet food:
Release Notes
It appears the changes to the browser version were made without notice; these notes indicate they are making the changes to the mobile version. Here is the relevant info from those notes:
- Phoenixes - To prevent being unable to use Pet Food on the Phoenixes to activate their Feeding Effects, we have disabled using the Ensorcelled Endowment Enchantment on these buildings. This had already been done on the browser version, but was still possible on Mobile until now.
This was done in August 2019 and Phoenix bldgs were the only pet food bldgs out at that time. The bears came next, but that event did not arrive until early September 2019.