Or were there too few to be a blip on the radar there in that era?
my goal as an actress? to remain on payroll
Other than a handful of foreigners, I don't think there were too many protestants in Mexico at that time. Besides, I assume they would be used to practice their religion in private for fear of persecution from the largely catholic population.
I'll answer your question since no one seems to have done it. Firstly, it's true that there were not enough protestants to make a blip, yet there were some as well as other religions. Now the post revolutionary constitution doesn't make the distinction between the churches. It did not single out the Roman Catholic church, but it was definately meant to affect that organization. In Mexico when referring to churches they most often use the term "culto" which does not mean a cult in the English language sense. It just means church or flock or members of a church, synogogue or mosque. So the short answer still stands: it was meant for all religion but would only target the Catholic.
Robert