It may be easier using the "Model Items" function where you can pre-select the feature from the left hand feature tree in the drawing (expand the view and pick the hole wizard feature. One of the icons in Model Items is for Hole Callouts.
There is a new "Advanced Hole" feature in 2017 you may wish to check out, useful when you want axially aligned holes of different types- although I think the callout function for it was removed in BETA due to issues.
Thanks for the tip, I'll check it out!
I dug a little deeper with this part in question and found I'd placed the clearance hole before the tapped hole. So I deleted the holes and placed the tapper thru hole before the clearance and I'm getting the dimensions I'm after again. Same geometry, different order...