Would you mind elaborating on this, please?

Are you talking about lucid dreaming? Access to the clear light a'la Tibetan yogas?

Are you able to reproduce those states while awake or in meditation? How did the state arise within the dream? Were you conscious of the changeover?

Most of the Merkabah stuff I'm aware of is basically a rehashing of "Pathworkings" from various mystery traditions, so it may be that you're just accessing your own internal symbology and its associated states.