Going to HBA, best timing is JQ but I need 2~Nope.
In fact, after you have booked on the JQ website, there is not a way to add the bundle.
Bundle must be added during the booking process.
Maybe if you booked a combo JQ flight, but within the QF main booking PNR, you might earn QFF points and QF SC, but if you made the booking on the JQ website, that's it, no changing of the booking, except maybe cancelling, and then rebooking.
But cancelling a JQ flight/s has its pitfalls.