Is wicca a religion? My opinion on that is simple enough to follow.
First, I would call wicca a religion because it has a following. There are people who believe in what wicca entails. True, no wiccan is the exact same in their beliefs and the religion itself has no big set denominations, but it is still a religion. There are generals that most wiccans share, there are stories they follow that are similar to the Bible. I, personally, am a wiccan who follows that there is one God, while other wiccans believe that there are multiple gods and goddesses, but that the high reigning are Goddess and Consort. There are rituals that most wiccans follow within wicca. So yes, I believe that does make it a religion.
Also, I believe that if someone has a solid following in something like this sort of thing that it makes it their religion. Some people believe in Christianity, some believe in Paganism, some Hinduism, and many others. And then there are those who follow wiccan. I see no reason not to consider it a religion at all. Who has the right to look at a follower of wicca and say; 'That is not a religion, why don't you pick a real one?' If we wiccans chose to make it a religion, to call it that, then that is exactly what it is. It is our right as people to see it as just that.
What makes a religion a religion at all, I think, is when people chose to begin calling it such. Time did not begin with religions, we made them by making rules and rituals and then saying; 'This is our religion.' That is how I think it works sometimes. We decided what things shall be religions. Few may follow true wicca, but that makes it no less than any other. And no one should ever belittle our religion, or any other for that matter. It is our business what we consider to be our religion. And if we want wicca to be that religion, then it will be, simple as that.
So, is wicca a religion? As long as there is at least one person with breath in their body on this year to be able to say 'yes' then I stand firmly by that wicca is, indeed, a religion. It has been one for hundreds of years, even if it might have been called something other than wicca. I am sure there are plent of people out there who would argue with me, but is it not a little hard to argue with someone who wants to call something their religion? If we really want it, then we will have it. Humans are stubborn that way.