Before Amigo, the last movie about American forces in the Philippines was John Dahl-directed The Great Raid (2005) which tackled World War II in the Philippines. Also in that movie was Bembol Roco who also appears in Amigo. Also in The Great Raid (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 3rd World Hero (2000), and a character created by Jose Rizal in José Rizal (1998).
Chris Cooper and Dane DeHaan would later re-team in The Amazing Spider-Man 2 (2014) as father and son Norman and Harry Osborn.