Omertà is almost certainly a reference to the (often exaggerated) Italian code of honor, while "rewenge" is a purposely silly German pronunciation of the word "revenge".
The actual audio drop used in the pod: "It means omertà. It means rewenge," is a clip from the British comedy program Peep Show, in which one character exacts his revenge on another. Peep Show is itself referencing Blackadder II.
A prominent example with context occurs 43 minutes into episode 101, "Hiding the Judd."