Many shuls in Eastern Europe have painted zodiac symbols (albeit in a rather symbolic manner) on the walls or ceiling. However, it is stated directly in the Mishneh Torah that one may not draw the constellations, and in Rambam's Commentary on the Mishna, it is stated that this does not refer to simply drawing the stars, but rather drawing the symbolic depictions of these stars and the like (for example, Venus as a young maiden). The sages clearly do consider the constellations to be real heavenly servants of Hashem, just as the cherubim are. So why was this not only permitted, but permitted in a house of worship?
The Mishneh Torah is clear that these depictions may not exist in a synagogue. However, certain things just make it through the fences the Rabbi's put up to block something. Zodiac symbols are found throughout many of the oldest synagogues in Israel and in other parts of the world. These synagogues were sometimes considered extra beautiful and ornate in other ways that would set them apart from what might be called the more "traditional" synagogues.
The Rabbi's in the Talmud struggled with the Zodiac use in the synagogues, as did the Rabbis after them, and the Rabbis after them.... And yet somehow it persisted throughout the centuries. Another one of these odd outlawed phenomena that withstood the test of time was round tefillin. Not only were round tefillin found in the Cairo Genizah, but an old depiction of tefillin also shows a cylindrical tefillin shape.
So the answer is no. It's not permitted to have zodiac symbols in a synagogue according to the Talmud and Mishneh Torah. It hasn't been permitted for a long time. But the children of Israel did it anyways.