That is simply false. The first problem is the word "religion", which, in common usage, is as if we were talking about different flavors of ice cream, and the atheist or "unbeliever" is some version of someone who simply doesn't like ice cream. Man is a religious animal in the sense that, as a rational animal, he must worship something he takes to be the highest good. The question is never "do I worship something" but "what do I worship" and "is what I worship the proper object of worship to which I owe worship". How do you know? Well, as in all cases, if no rational defense can be made of the claims of a religion, then there is no rational basis for giving our assent to those claims. So the question is: can a rational defense be made? Too often, people lazily assume such a defense cannot be made of any religion in principle. They simply take it for granted that that is the case.
So, if we interpret astrology as something explanatory, and there is no strong rational basis for it, then that means it is unlike those religious traditions that are rationally defensible. If astrology is a practical art, specifically, if it makes predictions based on some correlation between the positions of the stars and planets and whatever else, and this correlation happens to hold, then astrology is a more or less predictive model. (The "whatever else" also matter, as you could call the science of tides a kind of natural astrology because the moon does in fact have an effect on the tides.)
(FWIW, the Catholic Church rejects astrology, not as some "competing" doctrine, but as a pseudo-science and a superstition [0].)
[0] https://www.newadvent.org/cathen/02018e.htm