I am in your shoe currently, I hold an A320 enhanced and classic type rating with CFM-56-5B/A, Then our company brought a couple of 321s with V2500 engines and started running the courses to us in batchs, So I will probably get it next year however, Presently the Quality department have issued me a 321 approval with the exception of engine.
Since the 737s NG use CFM56-7BE, Then it's of no use as 320s use CFM56-5B/A so you will probably end up with a limited approval until you do the engine course such as my case.