At least not ONLY the act of creation. To me a Diety must actively participate in and be worshiped by his/her followers to actually be a Diety. It is possible for a sentient being to have created everything without being the Diety of what it created. WoTs creator is neither worshiped nor seeks worship.
Christian, Muslim and Hindu gods all actively participated in active worship and took part actively in the belief systems of their followers. This to me is a key differentiator.
The Dark One actually makes promises quiet similar to a Diety, but as a reader we know his most likely motivation is nihilism or possibly a total re-creation, in effect making him the creator of a new universe where he seeks to be actively worshiped. Given his loss he never actually achieves deification.
I submit that neither the DO or the Creator are no more than cosmically powerful entities. Perhaps in other Ages one or both are more than this, but not during the events of the 2nd, 3rd or 4th ages. I would argue that there are humans who have created concept in these ages that are consistent with various religions in the real world, but without the Creators active participation Imdo not see this as qualifying as "religion".