Not necessarily, teaching English jobs are still at a surplus in Santiago (though not to the degree they used to be), and it follows that you don't necessarily need a TEFL or CELTA to get a job, though the qualifications are always helpful. If you are going to look for a job teaching English in Santiago, I would definitely recommend you do it in late Feb or early March, December and January can be slim pickings with all the holiday time and what not.
You'll need a teaching degree if interested in teaching in the formal education sector, though - like a private school for instance.
You'll need a teaching degree if interested in teaching in the formal education sector, though - like a private school for instance.