There is no direct bus from POFQ to Boardwalk. There are several alternatives for indirect bus transport. During park hours, take a bus from POFQ to any park (MGM or Epcot would probably be best), then take transportation from that park to Bordwalk (from Epcot, this would involve walking through the park to Boardwalk; from MGM, this would involve the boat or a walk to Boardwalk). You could also take transport to the TTC or DTD and from there a bus to Boardwalk. Up to an hour would be a good amount of time to budget, once you take into account wait times. A direct car or cab ride would take no more than 10 minutes.