Hi Phil .
From all reports on various studio forums and websites that I have read so far (ie; not tried myself) ..., all claim that ...,

Midi over bluetooth introduces too much latency, and also has a tendency to not be as reliable in capturing all the notes compared to using USB or Midi pin cables.

Perhaps others here have tried it ? ..,

I have bluetooth setting turned off on my mac pro , as that in itself is another taxing feature on your CPU .

But if you want to test the latency for yourself .., open a DAW / set the click / then record single midi notes (on the click) as accurately as you can play them / then note how many ticks or milliseconds they got placed away from the gridlines ..,

Then repeat this experiment by first turning off bluetooth , and then connecting the midi cables / then repeat the same experiment as above (but via the cables) .., and note the differences

Note : many users have reported dropped notes also when using the bluetooth method.

My Specs
Computer : Mac Pro (late 2013) - OS Yosemite 10.10.5
Processor : 3.5 GHz 6-Core Intel Xeon E5
Memory : 64 GB 1866 MHz DDR3 ECC
Graphics : AMD FirePro D300 2048 MB
Interface : Avid Mbox 3 Pro
DAW : Pro Tools 12.6.0 (64 bit AAX)