In addition to the below modification to the text reference, I also added the following into the gameplay file under “improvements”:
UPDATE Improvements SET PrereqCivic="CIVIC_HUMANISM" WHERE ImprovementType='IMPROVEMENT_GOLF_COURSE';

Wasting your culture on reformed church sucks for a non-religious civ, so I changed it to the humanism civic. I replaced the +2 appeal bonus with this (reverted to +1), but you should be able to add this in underneath if you want both.

I also increased the amenity amount (AGB_GOLFCOURSE_AMENITY) at the bottom of the file to "2" in order to match the base amount for Gathering Storm.

Believe text file need to reference 'LOC_IMPROVEMENT_GOLF_COURSE_XP2_DESCRIPTION', which is the lattest Firaxis name for golf course improvement?

Thank you, golf courses are so weak. I still think even with this buff I think the still need more.

Мне тоже поле кажется слабоватым, но, возможно, ты немного перестарался )