Few months ago I tried to search for Youtube partnership networks that pay bitcoins, but didn't found anything except Creative Nation. I remember that I found announcement on Reddit about network who pay bitcoins, but their service doesn't works.
Partnership networks only pays in fiat and it doesn't looks that situation may change soon. Maybe Google don't want to support integration of bitcoin as payment option.
Partners are separate, though, and I doubt YT has any say in that. Basically, YT pays them in fiat, they then pay you in BTC. Most are just afraid to get involved because BTC still has a negative stigma attached.