I think you may be a bit confused, the "Manila Galleon" or Nao de la China" sailed from Acapulco Mexico to Manila in the Philippines with silver (not the other way around) as the silver was used to buy ceramics, silks, spices etc in East Asia for shipment back to Spain via Acapulco and Vera Cruz, Mexico and the Caribbean (Havana). Silver from Mexico (or further south in Peru) was also shipped to Europe and worked into church and domestic articles for use in Spanish America.