Hi Wazza,
The Gulf is not really well serviced by One World.
If non-OW, Probably from SIN, the best option is Qatar airways and hubbing out of Doha. QR has reportedly a magnificinet J class offering.
Alternatively, on some days, SQ flight to Kuwait via Abu Dhabi. So, I guess you could hub out of AUH to BAH/KWI.
Here's a left-field option, (not for the first-time traveler to India!), you could take the Qantas flight from SIN-Mumbai. Then from BOM, you could fly Jet Airways to BAH, and return on Jet Airways from KWI to BOM (and the QF-SIN). Obviously you'd need a one-way fare from BAH-KWI. If it were me, I'd take the KLM flight, it has a good 10.30pm departure time if you wish to depart BAH after work. Alternatively United also offer a fare on this BAH-KWI route if you wish to credit that to Star Alliance.
Although Jet Airways is not One World, it is a Qantas partner for points earning.
Finally, I'm unsure the departure date of your flight, but Kingfisher Airlines are joining One World within the next 12 months. Just replace Jet Airways with Kingfisher, if your dates coincide with their OW entry.