Can HL-36 act as RC controller for HL-36R on E-M5?

Yes, the FL-600R can be used in any mode (TTL, Auto, Manual and Off) if sitting on the E-PM2 or used with a cable (cheap chinese Canon-TTL-clone). At the same time it can control the remote FL-300R in TTL (+-5EV), Manual (from full power down to 1/128) and OFF.

The other way around? I couldn´t make it work until now and will have to resort to the manuals of both flashes when back home.