Do the AIs have bonus in spreading religions?

[gettingfat]

Anybody know the failure rates of converting a city already with one or two religions? I find it so hard and frustrating, meanwhile those religious frexk AIs is converting everything with ease, as if there is no cap in building missionaries.

 

[Refar]

The AI is bound to the 3 missionaries limit and does not have any bonus when spreading.

The chances of success for missionaries are explained here, by VoiceOfUnreason