Ahhh… I think I’ve found an answer!
Here’s a snippet from Google:
"At various times in Matthew, it says the “disciples” got in a boat (e.g. Mt 14:22). Is it plausible that this referred to all Jesus’ followers? Again, in Mt 19:25-28, Jesus speaks to his “disciples” and refers to “12 thrones, judging the 12 tribes of Israel” that will be theirs. See also Mt 20:17 which says “12 disciples.” The Last supper passage Mt 26:18-20 also refers to 12 disciples. Mt 28:16 refers to the “eleven disciples” (Judas had already betrayed Jesus).
Thus, it is quite clear that throughout the book of Matthew that the term “disciples” almost surely refers ONLY to the Twelve. And this makes sense: Matthew is the the most Jewish of the gospels and the Jews did not let just anyone make binding Scriptural interpretations! The notion of an authoritative hierarchy and the importance of tradition that came from Judaism were not done away with in the formation of Christianity.
Consequently, since Jesus is not speaking to a crowd of followers/disciples but to the Twelve in Mt 18 when he confers the authority to “bind and loose,” it is the Church leadership, NOT all Christians, who receive this authority."