So here are the relevant changes from G's upcoming patch notes:
Well/Water Mill are being changed to 0.2p/pop and 0.25p/pop, respectively; floating garden is 0.20f&p/pop
Agribusiness is now +1 Food to farms and +1 Food to pastures
Herbalist is now +1

to
jungle, no bonuses to
forest at all
Workshop is now

/

on
forest, no bonuses to
jungle at all
University is now

on
jungle, no bonuses to
forests at all
Battleship is now 1 range, but starts with Range promotion
Lumber Mill in jungle is now called "Logging Camp"
So this changes madrasah, Baan Chang, Andelgeverbgeiboop, nilometer and buffalo pound.
Madrasah - straightforward... though the base building is a bit more lackluster now.
Baan Chang - In light of the change, I vote for the 1

/

on
lumber mill and 1

/

on
"Logging camp". In the current iteration, forests have lost a ll but their first 2 food, and jungle has lost all but its 1st production, unless boosted by policies
Andelvasgedinkadoop - Add the +1

to farms/pastures, +1

for every farm in 3 tile range and +1

for every pasture in 3 tile range.
Buffalo Pound - I would make the scaler 0.2

(instead of

), since it stacks with water mill which can give the 0.25

. Then shoshone get 0.2

/0.25

with both
Nilometer - doubling the production scaler to 0.5

on that early a building is too high, IMO. Maybe 0.4

(2

for every 5

) instead?
Although, Flax does grow in Marsh so maybe you could let that particular feature stay for it.
I'm against this. Having improved tiles on top of marsh is unheard of. My pearls are clutched and I am ready to fall into the arms of the nearest southern gentleman at the thought of such a thing.
Actual reason though? Clearing marshes is unlocked at machinery and nilometer is 3 techs earlier. If flax spawned on marsh and a player couldn't work it for a full era they would be liable to punch a hole in their computer, and I don't want to be responsible for that.
I guess we need to make a hard agreement on this.
FLAX: Search in range of 3 around city
Floodplain -> River Tile -> owned unfeatured terrain (grassland/plain/tundra/desert) -> unowned unfeatured terrain within 3 tiles of city
No: hills/forests/jungles/mountains/oases/marshes/resource tiles/snow/water
(this is identical to what
@adan_eslavo already posted)
FIGS: Search in range of 1 around latifundium
Grassland/plain(with or without hills)->Tundra(with or without hills)->desert(with or without hills)->forest/jungle->marsh
No: mountains/oases/resource tiles/snow/water
In case of marsh/jungle/forest, remove feature
I don't think preference should be given to river tiles; as people have said, having plantations spawn on rivers actually kinda sucks because they are taking up good farming real estate