if you mean Scleropages Jardini and Scleropages Formosus, yes they are related and classified as bonytongues, but no they are not the same species.
Scleropages Formosus will come in various colors of different origin, and they have a higher demand with higher costs due to its endangered state. Only the farm-bred ones are being distributed to legal countries for the aquaria-trade.
whereas the Jardini and Leichardti are the only ones that dwell in Australian waters.