The simple reason that CL is listed seperately is that the Caster Level is not only something that the creator must meet but it also sets how hard the item is to effect with a dispel magic and sets variable effects of spells.
It is also seperate because Prerequisites do not have to be met by the creator themself, another person may supply a prerequisite but it is the creator who must meet the CL and pay the XP cost. This only strengthens the argument that the creator must meet the items CL because the rules seperate it from other prerequisites which can be met by someone other than the creator.
"If two or more characters cooperate to create an item, they must agree among themselves who will be considered the creator for the purpose of determinations where the creator’s level must be known. The character designated as the creator pays the XP required to make the item."
So if an item had a CL of 10 but a prerequisite of Caster Level 15 then a 10th Level caster can be the item's creator if another caster supplies the CL 15 prerequisite.
The sentence (for non potions, scrolls, wand) is quite clear. "the creator’s caster level must be as high as the item’s caster level". If you are the creator of an item you must meet the CL.