A city will be razed automaticly if its size 1 and has no culture
Thats why most of the time, in the ancient era, when u capture a AI's city, ur troops will burn it since the AI doesnt usually build culture city imporvs till later on,when most of the nearby land have been taken.
Thats pretty annoying cos the AI always has some settler saved somewhere on will build another city in the same place
So afaik no cities with wonders should b auto-razed. Maybe if the town hasnt expanded its cultural borders yet, (for instance if the wonder was built 2 or 3 turns ago), that could happen, but i doubt it
But answer the inicial question:
No, I dont raze cities in any circunstances. The reputation hit is too big to risk