The Vietnam War was fought very differently, with some zones of possible operation excluded for political reasons, in order to limit the spread of a small regional war fought to assist a troubled ally, which then morphed into a test of international will, with support provided by two major world powers. During the course of the fighting, the American people became first, disillusioned, and as time pressed on, vastly disillusioned, with riots and other anti-war activities at home. The final four years of the war were spent in trying to disengage, and after the completion of the American withdrawal, all funding for the South Vietnamese government was cutoff. Thus this war was very political, and poisoned American politics for a generation.
The Philippine War was quite different; there was little opposition at home, and stories from the battlefields seldom caused a stir. One of my grandfather's spent three years fighting in the Philippines, and later fought in WW I. Most of the serious fighting was in the southern provinces, against the Moro, a Muslim population that had likewise resisted the Spanish, and today resist the Philippine government. With very little foreign backing, they were limited to home-grown forces, and limited armaments and manpower. It just took some staying power to overcome the resistance. With little to no political opposition at the time, and no other pressing engagements, there was never much doubt that the Americans would prevail.
I'm here considering the entire time of engagement; the "formal" war ran from 1899 to 1902, but guerilla actions continued until 1913. The American's suffered about 2,000 casualties overall. For details, see Philippine-American War.