Abraham’s Bosom was part of Sheol. It was the good part. Sheol is sometimes translated as Hell, but it was not exactly the same as the Hell of the damned.
There is a lot of Harrowing of Hell material that points out that St. John the Baptist probably acted as Jesus’ forerunner in Sheol, too, alerting the Patriarchs that the Messiah was on His way. (And St. Joseph before that, as well as Simeon and Zechariah.) Obviously the various sermons and apocrypha do not have the same authority as the Bible, but it is close to big T Tradition.
A lot of the Patriarchs and prophets were saintly folks or even martyrs, but only St. Elijah, St. Enoch, and St. Moses seem to have been in Heaven before Jesus brought the righteous dead out of Sheol. (And there is dispute about them.)