M"B 25:42 makes it clear that we always follow Gemara over Zohar. And we similarly follow Bavli over Yerushalmi (as is clear from the Hirhurim article quoted in this related discussion).
However, do we follow Zohar or Yerushalmi?
M"B 25:42 makes it clear that we always follow Gemara over Zohar. And we similarly follow Bavli over Yerushalmi (as is clear from the Hirhurim article quoted in this related discussion).
However, do we follow Zohar or Yerushalmi?
According to Harav Yishak Yosef Shelit"a (En Yishak vol. 1 pg. 334) we follow the Yerushalmi over the Zohar.
Sources to support: Petah Hadvir 46c, Sede Hemed Kelale HaPoskim 2:5, Yabia Omer vol. 4 pg 39a).
In the discussion of the correct procedure for cutting the bread at the Shabbat meal, R. Joel Sirkes writes (Bayit Chadash O.C. siman 274) the following:
דאין עוברין על דין התלמוד מפני שהוא כך על פי הקבלה וכי היכי דאנו מניחין תפילין בחולו של מועד ע"פ תלמוד ירושלמי כמ"ש לעיל בסימן ל"א ולדברי הזוהר הוא חייב מיתה
We do not violate a Talmudic law when Kabbalah specifies a certain way, just like we put on tefillin on Chol Hamoed in accordance with the Talmud Yerushalmi, as I wrote earlier in siman 31, even though according to the Zohar this carries the death penalty.
This appears to be a clear statement that the Yerushalmi supersedes the Zohar.
However, R. Joseph Karo writes (Beit Yosef O.C. siman 31 ) that originally the Benei Sefard would put on tefillin on Chol Hamoed, but once they discovered what the Zohar said they stopped:
ועכשיו נהגו כל בני ספרד שלא להניחם בחול המועד כדברי הרא"ש ואחר כך מצאו שכתב רבי שמעון בן יוחאי במאמר אחד שאסור להניחם בחול המועד ועל פיו נמנעו מלהניחם בחול המועד וכן כתב מורי דודי הה"ר יצחק קארו ז"ל בתשובה
He concludes by saying that since this question is not explicitly clarified in the Talmud Bavli, no one has the guts to actively defy the strong words of R. Shimon Bar Yochai:
ומאחר שבתלמודא דידן לא נתבאר דין זה בפירוש מי יערב לבו לגשת לעבור בקום ועשה על דברי רבי שמעון בן יוחאי המפליג כל כך באיסור הנחתם
This would seem to indicate that the Zohar supersedes the Yerushalmi, in which case we would be left with a dispute about which supersedes the other. However, R. Karo is not necessarily assigning greater authority to the Zohar than to the Yerushalmi. First-of-all, it is possible that he holds that the proof from the Yerushalmi is not a clear-cut proof (i.e. perhaps the Yerushalmi is not actually conflicting with the Zohar), and second-of-all, it is possible that his reasoning is not based on measuring authority but instead based on what he wrote in the last line.