MANILA, Philippines — A plunder case against former House Speaker Martin Romualdez has been filed by the Office of the Ombudsman in the Sandiganbayan. Romualdez and former Ako Bicol Rep. Zaldy Co have been accused by Ombudsman investigators of alleged “concerted and coordinated acts” in “unlawfully amassing, accumulating, and acquiring ill-gotten wealth” amounting to approximately P56