And the first revolt is generally a sign of flipping but usually it will flip on the second revolt but on the higher difficulties (above noble), I've had one city that only flipped on the third revolt.
But yes, put the cultural pressure on plus religious conversion would usually work. Also I've sent some spies at the later stage to cut the road around that city (if it is not engulfed by your boarder doing so will make sure no health and happiness resources could get into the about to flip city. That'll speed up the subsequent revolt. If it is being engulfed then second revolt flipping is a sure thing even on the higher level) and destroy the improvement (if you consider save-and-load a cheat, then you'll have to risk the diplomatic repercussion if your spy fails).