Here's the thing though...in Class D you can expect traffic information on IFR & VFR...that is your service. Under radar control service you could expect more updates on traffic - doesn't sound like you did though...did you call "visual" with the traffic? (In which case I doubt you'd get further updates as the point of traffic info is to "see and avoid")
It's really difficult to tell what the traffic situation was from your post...was it just you and the other VFR flight? Was there IFR around? Other VFR?
What was the limit of the control zone vertically? Could the controller have given you higher without co-ordination with another controller/unit? Did he/she actually clear you at an altitude or was it "not above" an altitude? Have to say the other VFR pilot showed good practice in one respect if he/she did call to say he/she was at 2,300ft.
The whole point of Class D is that ATC don't need to separate VFR from other flights. ATC relies on VFR being able to "see and avoid" other traffic which is why traffic information is passed.