This is a mind-boggling question and the answers are very subjective. Many foreigners buy books, tapes, visit websites and learn the Filipino language when they have to stay for a vacation, or visit their loved ones in the Philippines. It all depends on the objectives and interests of a person to learn the Buy Barong Tagalog native language or not.
Definitely, if you learn Filipino you can get accustomed to their food, culture and place. You will not have any hassles when you want to explain your point to the local cab-driver or room attendant in a hotel.
Filipino language itself is a combination of various other languages. It has influence from many Indian languages like Sanskrit, Hindi, and Tamil. It has borrowed words from Chinese by trading with them. And, above all Spanish and Americans had colonies in Philippines so it has words from Spanish and English. This language is still in an infancy stage and is still developing.
Tagalog is the old native language and it is like a local dialect but when it became an organized language registered as national language it became Filipino. In simpler words, Filipino has Tagalog dialect but Tagalog does not have Filipino words. The second language taught in school is English and at the graduate and undergraduate level everything is taught in English. So there is absolutely no need for a foreigner to take pain and learn Filipino.
Very often foreigners speak Filipino when they visit a place or purchase something or communicate with the taxi driver or attendant and they reply in English. Even upscale Filipinos speak English and will just praise your language skills but converse only in English.
Of course, you will benefit if you learn Tagalog or Filipino and make your trip hassle-free and more enjoyable but it is all depends on the purpose of visit. In Philippines, even vendors and hawkers can communicate in good English. You can bridge the cultural divide by learning Filipino and understand and have all the benefits from your trip.
Filipinos are very hospitable and they make the foreigners comfortable and are multi-lingual and make the foreigners feel home by speaking to them in their language. But if English is not your language then it will be better if you learn Filipino.
Most Filipinos will be impressed when you speak Tagalog or Filipino language. They will be surprised and give you a big-sweet smile that you will warm your heart.