I'd say lets run with some fun ones in that case.
I have no idea how strong you want the pantheons being, but I'm guessing somewhere around 50% more power or double the power?
Ancestor Worship - +3 culture in capital +1 faith/4 citizens.
Hard to know what to do with, just increasing the culture isn't a good idea because it will snowball heavily. Maybe something like:
(50%) - +3 culture +2 food in capital, +1 Faith/3 citizens.
(100%) - +3 culture in capital +1 culture in other cities, +1 Faith/2 citizens.
Cult of Nature - +2 culture/faith from natural wonders.
I honestly feel like this pantheon needs a rework in general, I find the yields on mountains completely stupid and creates way too powerful combinations with Machu Picchu and an observatory, for that reason I'm not even going to include it here.
I also find this pantheon in general pretty hard to increase upon, as natural wonders are way rare and you already get a 50% bonus from them. If I had to do something I would perhaps do it like this.
(50%) - +2 culture/faith/food from natural wonders
(100%) - +2 culture/faith/food/production from natural wonders.
However, these are both really a lot worse than the other options as imho, the base pantheon isn't very strong.
I'll place this one on ice for now.
Dance of the Aurora - +1 Production/Faith/Culture from improved tundra-tiles.
Desert Folklore - +1 Food/Faith/Gold from improved desert-tiles.
Yes I know it only works on actual resources, but that takes too long to write.
Anyways there are a lot of creative ways to handle this one (and the desert one).
You could either just buff the existing numbers. add something to it, or completely change it to something with a similar effect.
All these examples are aimed at Dance of the Aurora, but they pretty much applies to desert folklore aswell.
Some examples:
(50%) - +1 Production/Faith/Culture from improved tundra-tiles. +1 food on flat (non-hill) tundra tiles without resources on them.
Turning tundra-tiles into hard-to-improve grassland-tiles.
(50?%) - +1 Food/Production/Faith/Culture/Gold from improved tundra-tiles.
Just pumping up the numbers, added the yields from the desert folklore to it.
(100%) - +1 Food/Faith on all tundra-tiles.
Pretty much a pimped up version of the old dance of the aurora, could create an interesting situation where the Celts can adapt to their surroundings and turn into a pseudo Arabia/<Funak's Russia>.
(100%) - +2 Production/Faith/Culture from improved tundra-tiles.
Fertility Rites - +2 Food +1 Faith +10% growth from Shrines.
Hard one again, just pumping up the numbers could be a solution, but ti's rather boring. One could combine it with Goddess of Love I guess. But that doesn't really sound very fun either.
(50%) - +2 Food/Faith +15% Growth from shrines.
(100%) - +2 Food/Faith +25% Growth from shrines.
God of War - +2 science from barracks. +Faith from kills.
Hard to do anything with this other than just increasing the numbers.
One could also combine it with another existing pantheon, maybe Faith Healers or Goddess of Protection?
Goddess of Festivals - +2 Culture/Faith from luxuries
(50%) - +3 Culture/Faith from luxuries
(100%) - +4 Culture/Faith from luxuries
Goddess of Love - Gain +5 Faith and +3 GAP whenever a city grows.
There is some options here as well. Bumping up the numbers, adding other yields to it, making cities grow faster somehow or adding some similar effect from another pantheon to it, maybe Religious Settlements.
Monument to the Gods - +2 Faith +1 Culture from world wonders, 15% bonus while building ancient/classical wonders.
(50%) - +2 Faith +2 Culture from World wonders, 15% bonus while building wonders.
(100%) - +4 Faith +3 Culture from World Wonders, 15% bonus while building wonders.
Sacred Path - +1 Faith from every 2 jungles, +1 Culture from every 2 forests.
I actually find this pantheon currently extremely under-powered with the changes to improvements and forest/jungle. Maybe the base pantheons should be reworked somehow.
(?%) - +1 Faith from jungles, +1 Culture from forests.