Bandolera literally translates to "female bandit," like a woman who wears a bandolier (a belt for bullets). In the fiery world of salsa music, however, it's a powerful slang term for a heartbreaker or a "player".
When Oscar De Leon calls his ex a "Bandolera," he's painting a picture of a wild, untamable woman who stole his heart and broke the rules. It’s a much more dramatic and exciting insult than simply calling someone unfaithful, perfectly capturing the passion and pain of the song.
Venezuelan salsa legend Oscar De Leon is completely fed up in this song. He's singing to someone who keeps playing games with him, telling them, "Si te busco por aquí, me sales por allá" (If I look for you here, you show up over there). He's tired of the chase and the suffering, and he's ready to make a bold prediction about their future.
He warns this person that for their bad behavior, they will pay. The song's title gives away the main point: "Llorarás y llorarás / Sin alguien que te consuele" (You will cry and cry / Without anyone to console you). He believes that only then will they understand that being cheated on hurts. And when they finally come back asking for forgiveness, it will be too late. He's already decided, "Ahora quien ríe soy yo" (Now the one who laughs is me), and he's off to live his life exactly how he wants.