Is there a code requirement for the concrete coverage over 1/2" anchor bolts? Another words how close to the edge of the concrete on top of a wall? Or would we just follow 1/2" rebar coverage?

The only one I've seen is 5 times the diameter for lag anchors. So if you have a 1/2 " lag anchor you need to be 2.5" from the edge. I would think the same for anchor bolts. The 1.5" for rebar is to make sure the rebar is covered, but there is no pressure on rebar like anchor bolts.

Are we talking cast-in-place J bolt anchors or drill and drop in wedge or adhesive anchors?

What are you attaching to these anchors?

The 2012 IBC specifies a minimum concrete edge-to-anchor-center distance of 1-3/4" for anchors attaching a bottom plate to concrete foundation which makes sense when you are dealing with a 2x4 bottom plate.

https://codes.iccsafe.org/content/IBC2012/chapter-19-concrete