Folks,
I may have missed something here, and later additions may change this. But currently, what I see is that a city with only the base improvements will grow to a pop of 28-29 before stopping due to prestige. The only way I've found to increase prestige is by the housing research line, and building estates/mansions. While this is probably early, you may want to provide other options earlier in the tech tree, rather than something that's 100+ turns down the civ line before you can grow to the next level.