Philippines is an excellent choice for learning how to box. Though not all gyms are open to foreigners, There will be a few good ones that will cater. It depends on what you want. If you want hardcore training then you will have to go to a province and live there. It will be very difficult since most gyms aren't really made to cater westerners. Most gyms are just for competition. I would highly discourage going to provinces to train as the environment is very different. The food is limited, there might be no electricity, the heat is unbearable and you are light years away from civilization.
The training in the city isnt that bad but more or less you have to find a hotel to live in coz the gyms doesnt have rooms. I can help you find a good gym that will surely improve your boxing skills. Though the training in the province is more hardcore, the training in the city is similar but with reduced intensity. You can talk to the trainers if you think you want your training to go up in intensity. In most cases you need to pay for a sparring fee ($6 is good enough) and expect the heaviest sparring sessions you will ever experience.
Hope this helps to everyone who is considering PI to train boxing. If you guys have some Q's PM me.