Not sure if anyone else discovered this, but I think I found the cause of the diminished bokeh depth of field effect on PC when compared to the PS4 version: broken built-in AA.
I did a couple screenshot comparisons, and it looks like the PC version's built-in AA solution isn't working as intended, which severely lowers light output and fine detail on any and all of the game's lights sources.
Screenshot comparison here to show the diminished light output/detail (some far off light sources are entirely obscured by the AA):
http://screenshotcomparison.com/comparison/132512
And another to show how the diminished light sources affect the bokeh depth of field:
http://screenshotcomparison.com/comparison/132513
Last comparison to show the diminished detail with in-game AA enabled (note the sign directly ahead of the Batmobile) VS SweetFX SMAA:
http://screenshotcomparison.com/comparison/132515
Obviously, for whatever reason, they had a difficult time porting over the post-process AA. For those still playing, and have in-game AA on, I'd definitely recommend disabling in-game AA and injecting SMAA until they fix this.