When I put you itinerary in
OW Validator get
1: HBA-SYD: 1st of 4 (Southwest Pacific)
2: SYD-HNL: intercontinental
3: HNL-DFW: 1st of 6 (North America)
4: DFW-MIA: 2nd of 6 (North America)
5: MIA-PTY: 3rd of 6 (North America)
6: SJD-DFW: 4th of 6 (North America)
7: DFW-YVR: 5th of 6 (North America)
8: YVR-JFK: 1st of 1 (North America Transcon)
*8: YVR-JFK: 6th of 6 (North America)
9: JFK-DUB: intercontinental
10: LHR-IST: 1st of 4 (Europe)
11: BUH-LHR: 2nd of 4 (Europe)
Error!!! No oneworld service exists BUH-LHR