Before Amigo, the last movie about American forces in the Philippines was John Dahl-directed O Grande Ataque (2005) which tackled World War II in the Philippines. Also in that movie was Bembol Roco who also appears in Amigo. Also in O Grande Ataque (2005) was Cesar Montano who, just like Joel Torre, also plays Jose Rizal in José Rizal (1998).
The lyrics of the ending theme was written by Jose Rizal. Joel Torre plays 'Jose Rizal' in Bayaning 3rd World (2000), and a character created by Jose Rizal in José Rizal (1998).
Chris Cooper and Dane DeHaan would later re-team in O Espetacular Homem-Aranha 2: A Ameaça de Electro (2014) as father and son Norman and Harry Osborn.