The Labor code prohibition on asking about marijuana charges does not apply to 11357(a). Despite the fact that you didn't have concentrated cannabis, you plead that you did and that's all that matters.
432.8. The limitations on employers and the penalties provided for
in Section 432.7 shall apply to a conviction for violation of
subdivision (b) or (c) of Section 11357 of the Health and Safety Code
or a statutory predecessor thereof, or subdivision (c) of Section
11360 of the Health and Safety Code, or Section 11364, 11365, or
11550 of the Health and Safety Code as they related to marijuana
prior to January 1, 1976, or a statutory predecessor thereof, two
years from the date of such a conviction.
However, all that is neither here nor there. The reading on the previous section 432.7, says that a CALIFORNIA private employer also can't ask about EXPUNGED CALIFORNIA offenses (which are for practical matters dismissed).
Government employment and license applications however can INDEED ask this (and won't have that 437.8 exception on then application). In this case you'd be safer to list the conviction and say it was dismissed/expunged.