Well, one of the best end-game pantheon beliefs is still available: That "+30 healing when adjacent to a city" applies to aircraft. Which is outright broken since it basically guarantees that your aircraft will always be at a full health - either by taking a break every few turns, or if they have air-repair, just all the time forever.
Sadly, the "+15% production" (per follower, but eh every city gets that eventually) one is no longer available.
Thus
[x] Fertility Rites
Yes, it won't work without a religion. However, getting one is not actually too expensive in my experience.