How did dominating the philippines benefit spain?

Spain and Portugal were bound by the Treaty of Tordesillas, so the Spanish had to sail westward and travel through the Americas to get to the Pacific and finally the Philippines. It is also their only direct access -- meaning without going through intermediaries -- to the east Indies, as all other parts were to be the domain of the Portuguese. Further, as Spain faced increasing competition from their rivals the English, Dutch, French in the Atlantic world, their Pacific route was inaccessible to these rivals until much later.