All modern editors and PCBE assume the identity of the Presbyter Peter mentioned here with Peter [982], who is recorded as the first of the presbyters of the church of St Crisogonus in the inscription [2139] from AD 521. However, this identification is not certain, especially because of different presbyters of St Crisogonus mentioned in both inscriptions: Micinus here, Crisogonus, Catellus, and Gaudiosus in [2139].
There is no indication that Bonifatius was a blood relative of Valentinus or Xystus. It is rather unlikely: the post seemed to be a burial place for the presbyters.