I found commentaries on the bracha of Binyamin Vzos habracha 33:12 some of whom give the reason of not bowing and some other reasons. See Rabbi Scher below who connects all the comments on Binyomin (including the two in the question) to a unified explanation.
And of Benjamin he said, "The Lord's beloved one shall dwell securely
beside Him; He protects him all day long, and He dwells between his
Rabbi Yitzchak Scher/ Kollel Zichron Amram/Yeshiva of Greater Washington writes in The Spark Within that the connection is not that Binyamin did not bow or that Binyamin was not involved with the sale of Yoseph, but that these and other events (such as being born in Eretz Yisrael) meant that
Binyamin represents to us this immutable point of purity within every
Jew. Binyamin represents the part of Klal Yisroel that remains pure,
pristine and innocent, no matter what. In his entire lifetime, evil
does not touch him and he does not touch evil. He is the paradigm of
In the Beis Hamikdash, there is one room which always remains holy,
pure and pristine. The Kodesh Hakodoshim (Holy of Holies), which was
only entered once a year, by the Kohen Gadol on Yom Kippur, is a room
that represents the deep, eternal, and intimate relationship between
Hashem and the Jewish people. This room is that point in the world
that remains holy, untainted, and uncorrupted by evil. It was a small
beacon of spirituality, a slice of another world, within the confines
of this world. This room was appropriately situated in Binyamin’s
portion of Eretz Yisroel. This is the meaning of Moshe’s blessing to
the tribe of Binyamin: “To Binyamin he said: ‘The dear one of Hashem.
He will dwell securely with [Hashem]. Hashem protects [Binyamin] and
rests His Presence upon him’ (Devarim 33:12, see translation of
Onkelos and other commentaries).”
Priority Number One cites the Ntzi"v as quoting the medrash.
The Netzi”v, Zt”l, Zy”a, gives another reason. He explains that the
Medrash says that the reason why the Beis HaMikdash was built in the
portion of Binyamin was because he was the only one who did not bow
down to the wicked Eisav. Since at the time of the bowing, Rochel was
already pregnant with Binyamin (cf. Targum Yonason Ben Uziel), Yosef
blocked Rochel from Eisav so that even in the fetus stage Binyamin
should be spared from bowing down to Eisav.