Back in the old days of ST1, if you selected PHP it would actually show HTML, to the confusion of many.
It seems ST3 has restored this behaviour of showing HTML in the status bar rather than PHP.
Maybe the status bar is looking at the root scope? I know the context menu definitely has a
✔ next to PHP
And the following confirms it:
Not quite sure, but they both seem to include each other. I just took a look.
text.html.basic is the root scope for either grammar the way it's set up