I have been an ACF member for 11 years and certified for almost five, which means I get to go throough the renewal process. Culinary school is not necessary to become certified, nor is an apprenticeship. I had neither, and am doing fine form learning from the best of the best in the areas where I worked. What I did do, however, was join the local ACF chapter. It may seem like a chunk of $$ to join, but the networking, the learning formt he chefs and the educational seminars at the meetings, and just being around chefs is more than worth the $$. I can say that being certtified and especially being an ACF member has gotten me jobs and into interviews. I got into interviews before the job was posted because of the ACF chapter networking.
To answer your question about ACF certification being recognized internationally, it is. ACF is a member of WACS, the Worls Association of Cooking Societies, (I think that;s what it stands for). The current WACS president is from the US and is an ACF member. Any country that recognizes WACS, which includes most industrialized nations, will also recognize ACF. You can check out the ACF website:www.acfchefs.org
for the location of the closest chapter to you.