Since this origin question excludes the obvious catalyst "Chiron", I'm going to throw in a token example: CS Lewis' Narnia series has Centaurs skilled in astrology.
They can do astrology and are skilled in healing.
From that same article, see the quote:
In Greek tales, centaurs were nearly always a wild race who were violent, womanizing, and usually intoxicated. The centaurs of Narnia are based on a unique and well known Greek centaur, Chiron, who, unlike all the other centaurs, was a noble, wise, and powerful being.
I believe there is an understanding that if there are noble/wise centaurs, they are based on Chiron as he is a very popular early centaur. All others in Greek mythology represent man's base desires. Drunkenness, lust, battle, feasting, unbridled passion and chaos were the ream of non-Chiron centaurs.
So, while you're explicitly cutting Chiron out, any pre-Narnia examples of astrologically skilled centaurs are most certainly also based on Chiron.
Chiron is also known as: "Centaurus" who was said to have done the original pairings of stars to make the constellations:
Centaurus was the first person to group stars into constellations and taught others how to read them. One explanation of the constellation is that Centaurus put a picture of himself in the sky to guide his sailor friends the Argonauts.
Chiron and Centaurus may or may not have been always the same person, but they typically are.