Hmm. Your calipers should only have one bleeder valve. If you have two bleeders the manufacturer made them that way to fit on left or right of vehicle. Nevertheless you should always bleed from the top because that's where the air will be. The air bubbles float in the fluid cavity and if you bleed from the bottom the air will never come out.
They are aftermarket and you confirmed my thoughts they were made for either side.
I pulled one of the OEM's out of the trash and they also have two spots for bleeders but on each side the upper has the bleeder ad the lower has a plug.