The phrase "to whom" refers to both James son of Zebedee and his brother John.
# the name Boanerges, that is, sons of thunder
Jesus called them this because they were like thunder. AT: "the name Boanerges, which means men who are like thunder" or "the name Boanerges, which means thunder men" (See: [[rc://en/ta/man/translate/translate-names]])
# Thaddaeus
This is the name of a man. (See: [[rc://en/ta/man/translate/translate-names]])