If you roll a 6 at the Dungeon's Treasure Chamber, It says

you go directly to the Crown of Command. My question is, Does this mean you don't need a Talisman?

Thanks

The Talisman allows you to pass the Valley of Fire to the Crown of Command space, since you have directly bypassed this and are at the Crown. You do not need a Talisman.

If however you leave the Crown of Command space, then you can't return without one.