Texas Penal Code
§46.11. Penalty if offense committed within weapon-free school zone.
(a) Except as provided by Subsection (b), the punishment
prescribed for an offense under this chapter is increased to the
punishment prescribed for the next highest category of offense if it
is shown beyond a reasonable doubt on the trial of the offense that
the actor committed the offense in a place that the actor knew was:
(1) within 300 feet of the premises of a school; or
(2) on premises where:
(A) an official school function is taking place; or
(B) an event sponsored or sanctioned by the University
Interscholastic League is taking place.
(b) This section does not apply to an offense under Section
46.03(a)(1).
(c) In this section:
(1) "Institution of higher education" and "premises" have the
meanings assigned by Section 481.134, Health and Safety Code.
(2) "School" means a private or public elementary or
secondary school.
Since this was added in 1995, the same year as the CHL laws, I believe that is exacty the definition of school that applies to CHL.
Texas Health and Safety Code
§481.134. Drug-free zones.
(a) In this section:
(2) "Institution of higher education" means any public or
private technical institute, junior college, senior college or
university, medical or dental unit, or other agency of higher
education as defined by Section 61.003, Education Code.
I can't believe I never noticed that before.

Charles?