I'm not sure if you're referring to a specific encyclical needing to be dedicated to the issue, but as a Catholic, I have often heard the bride/bridegroom analogy used as one of the reasons for an all-male, all-celibate clergy.
No, all I'm saying is that, while individual preachers may use the Bride-Bridegroom Metaphor, that argument has not been used in the official magisterial documents on the issue, as far as I can see.