From a book published in 2002,
Caesar's Legion by Stephen Dando-Collins.
Pompey:
According to Cassius Dio, legions marked with an asterisk were still in existence in a.d.233.
1st Legion:
Founded by Pompey the Great in 84 b.c. Believed to have been dis-banded by the emperor Vespasian in a.d. 74.
2nd Augusta Legion: Founded by Pompey the Great in 84 b.c. Granted “Augusta”title, meaning “Augustus’s,” by the emperor Augustus circa 25 b.c.*
3rd Augusta Legion: Founded by Pompey the Great in 65 b.c. Granted “Augusta”title by the emperor Augustus circa 25 b.c.*
4th Macedonica Legion, later 4th Scythica Legion: Founded by Pompey the Great in 65 b.c. Took title “Macedonica” circa 33 b.c., when its recruitment was transferred from Spain to Macedonia. Believed to have been granted “Scyth-ica” title by the emperor Marcus Aurelius in a.d. 179 for victory over a Scythian tribe, the Cotini.*
5th Legion, later 5th Macedonica Legion: Founded by Pompey the Great in Spainin 65 b.c. Recruited in Moesia in a.d. 60. Believed to have been renamed “Macedonica” in a.d. 80, when the legion’s recruitment was transferred from Moesia to Macedonia.*
6th Victrix Legion: Founded by Pompey the Great in 65 b.c. Granted “Victrix”title, meaning “Conqueror,” circa 25 b.c. by the emperor Augustus.*
7th Claudia Pia Fidelis Legion: Founded by Pompey the Great in 65 b.c. Granted“Claudia Pia Fidelis” title, meaning “Claudius’s Loyal and Patriotic,” following the Scribonianus Revolt, by the emperor Claudius in a.d. 42. The “Pia Fidelis” soon fell into disuse.*
8th Augusta Legion: Founded by Pompey the Great in 65 b.c. Granted “Augusta”title by the emperor Augustus circa 25 b.c.*
9th Hispana Legion: Founded by Pompey the Great in 65 b.c. Granted “Hispana” title, meaning “Spain’s,” by the emperor Augustus circa 25 b.c. Apparently wiped out by the Dacians in a.d. 86 and never re-formed.
20th Valeria Victrix Legion:
(A.) 20th founded by Julius Caesar in 49 b.c.
(B.)Valeria (meaning “Powerful”), founded by Pompey in 84 b.c., was given vacant 20th number by the the emperor Augustus in 31–30 b.c. Augustus granted the legion the “Victrix” title circa 25 b.c.*
21st Rapax Legion:
(A.) 21st founded by Julius Caesar in 49 b.c.
(B.) Indications are that the Rapax (meaning “Rapacious”) was founded for Pompey in the same year and originally called the Indigena, the “Native” or “Home-Grown” Legion. Given vacant 21st number by the emperor Augustus in 31–30 b.c. The 21st Rapax was apparently wiped out by Dacians in a.d. 86;never re-formed.
Although the above was founded by him or attributed to him, it can't be said for certain that they were with him during the civil war.
