iMacs had BT 4.0 since the Late 2012 model. Mac mini and MacBook Air: Mid 2011. MacBook Pro (incl. rMBP): Mid 2012.
There weren't any Apple devices with Bluetooth 3.0; they went from 2.1 + EDR to 4.0.
Once they have, you'll be able to view a graph of their reputation gained over time.
Here's a preview of what the graph will look like:
No reputation gained yet.