From: San Antonio, TX
For 'credit', you need to get the fuel and oil to where they can be used to produce HI. Unused, ultimately recaptured fuel gets you bupkis. Same with the oil. That's the ultimate use (well, that and refueling the odd ship or two), so wherever they can be used for that efficiently will suffice.
The home islands, particularly Kyushu, have sufficient oil and fuel to keep their industry running for a bit. But their reserves must be restocked anew or else your HI production will ultimately suffer. If this happens, bad joss on you.
I don't think you want to 'stockpile' per se. But interim ports such as Shanghai, Port Arthur, Manila and Singapore should be floating in excess oil and fuel just waiting to get put on a TK convoy back to the HI. I try to keep my production centers constantly 'dry' and dump in these major (waste-free, large) ports. There is no need to stockpile then. Furthermore, I think stockpiling per se may muck with the inherent overland movement of fuel and oil across the Chinese subcontinent. As I'd just as soon have my 'magic road' working, I won't muck it up with stockpiling orders along the route.