Technically speaking then, the tar utility cannot compress or encrypt per-file, but the tar format can be used for this, and since we're talking about format then the tar format can accomodate the requirements. It's just that there's no tool doing it at the moment.

(A counter point: while each file could be compress and encrypted, there's nothing in the tar format that explicitly says so, meaning that each file would have to be probed to determine if it was compressed or encrypted)