It has been 25 years since I read Jung's book on synchronicity, but there is a summary at the back of the book describing the acausal conncecting principal.  While I can see that there are similarities in the 2 philosophies of Astrology & Synchronicity, I do not see that the primary source (Jung) was referring to astrology at the time that he described the principal.

However, I am willing to re-read any (few) pages of Jung's works you cite.