If you have notice that entry on to a property is forbidden, then continuing to do so is criminal trespass (and committing criminal trespass while armed is a Class A Misdemeanor in Texas). I don't see how the 30.06 sign could be effective notice to CHL holders; but not effective notice to others that entry is forbidden.
The wording of the 30.06 sign and the wording of the 30.06 law are very specific and clearly apply only to those with CHLs.
Here's the wording of the sign. It would take truly heroic measures to twist the wording of the sign apply to anyone other than a "holder of a license to carry a concealed handgun" who is "licensed under Subchapter H, Chapter 411, Government Code (concealed handgun law".
"Pursuant to Section 30.06, Penal Code (trespass by holder of license to carry a concealed handgun), a person licensed under Subchapter H, Chapter 411, Government Code (concealed handgun law), may not enter this property with a concealed handgun"
Here's the law.
The law is painfully specific about who it applies to and who commits and offense by disregarding a 30.06 sign.
"TRESPASS BY HOLDER OF LICENSE"
" license holder commits an offense "
"entry on the property by a license holder "
""License holder" has the meaning assigned by Section 46.035(f)"
Perhaps a property owner could post another sign with more general wording that would keep out non license holders, but I don't see how anyone could interpret 30.06 to apply to anyone other than license holders.