CyanogenMod 12.1 development has begun for the only variant of the LG G4 that can currently be bootloader unlocked and rooted, the H815 European model. The developers now have access to the github and device tree, and have already put together some test builds. So far these builds are not ready for mass consumption and are strictly for development purposes. They aren't even booting past the LG screen. The good news here is that progress is being made. Hopefully there will be some breakthrough on a bootloader unlock method for the other variants, as that has still not come through yet. Head to the link below to follow the progress of this project.
via XDA