you don't 'have' to have the associated perk, but if you do have it you can improve them 2x as much as if you didn't have it. So if you have the steel smithing perk, you could level it up to legendary status sooner than if you improved the ebony without the perk, because without the perk the level you can upgrade to is associated with your skill rank (have to be level 100 to level up to legendary...)
thanks. yeah i just saw that with out the perk i need to be around level 196 to get a legendary status with wont be hard since my enchanting and alchemy are maxed out for those categories so between potions and enchanting a few things it should be able to reach legendary status with out wasting additional perk points in the tree.