According to http://www.colonizationfans.com/liberty-bells.html :
"Colonists are also educated faster in a colony with high Sons of Liberty membership."
How much faster?
Can't be certain but a vague memory is suggesting 50% to me.
I suggest shaving off one turn if SoL > 50% and two turns if SoL = 100%.
And adding turns when the usual tory penalties apply?
Sounds good, but I don't know if the original game does it.
Confirmed in Original Col; Training in a city with <50$ SoL required 4+ turns for Fisherman, at 100% I got it in two. Similar difference with Farmer.