Just want to respond to this. Philippines was under Spain at the time hideyoshi was in power in Japan. Does this mean Spain paid tribute to Japan? Because philippines as a nation or philippine national identity doesn't exist yet in the 1590s.
Like I said, the whole thing could be a fiction. More likely, I suspect, Hideyoshi rather optimistically interpreted diplomatic gifts or gestures as "tribute" in order to make his position seem more impressive to the recipients of his letter.
Otherwise, just how thorough was Spain's control over the Philippines at this time? It seems to me that some regions maintained something close to autonomy for many years. One of these chiefdoms (or whatever they were) might have sent tribute to Hideyoshi, and he either interpreted, or spun, this fact to make his position look better. I may be wrong about this, of course.