However, the Global Explorer fare has restrictions on backtracking and transfer points.

At least this is the case in India where no Oneworld fare is available.

Actually, indogulf, the restrictions on the Global Explorer fare is that it is limited to 28500 miles. You can still do: SYD-HKG-LAX-NYC-LHR-SIN-SYD. Or I managed a : SYD-HKG-JNB-LHR-SIN-SYD, without any problems.

I wonder why India does not have any rates for oneworld fares?

C340 - The rules that I mentioned were those ex. India. The Australia rules (and others) may very well be different.

Actually, I just booked one from India and they objected to the PIT-JFK-PHL sector as being backtracking even though it was only for a connection.

As for why they don't do the Oneworld RTW fare I don't know since BA,QF,CX all have quite a few flights to and via India. I'll have to ask the BA office this question.

Actually oneworld does have the Global explorer fare from India but only in economy class.