Limited to Sega Naomi 1 for now. Atomiswave to GD-ROM conversion games can also work, some of them might have some issues though.
To read more about this and other enhancements made to the Reicast cores, please read this article -
The next RetroArch version is coming soon. On top of that, now that Sega Naomi is more or less working (albeit in a preliminary state), it is getting time to have Model 3 arcade game support with Libretro/RetroArch by way of the SuperModel emulator! Stay tuned.