Monergism and Synergism refers to "sotieriology" (how God saves), so when you start to talk about things like "baptism" you are getting into ORDINANCES (done because God said so) vs SACRAMENT (done because they contain power and are the actual MEANS that God uses). Protestants generally fall on the side of Ordinances and Catholics fall on the side of Sacraments.
Sotieriology debates/discussions typically center on "Grace" vs "Works" and TULIP (in some form).
If you really want to talk about Baptism, then the only important question is this:
"CAN GOD SAVE WITHOUT BAPTISM?"
- If God can save without baptism (like the thief on the cross), then it is "monergistic" ... God does not NEED it to save.