Does a conviction for theft of service (31.04) count as a prior conviction for "any grade of theft" used to enhance a theft to a state jail felony?

Sorry not to be more definite. There is case law that says that Burglary, Credit Card Abuse, and Forgery are not "Theft offenses", but none that I can find that turn on the distinction between "Theft" and "Theft of Service" (or "Theft of Trade Secrets" for that matter).
My position is that if the prior is a Chapter 31 offense and has "Theft" in its name, it is a theft offense, and is available for 31.03(e)(4)(D)and, conversely, unavailable to enchance a theft-third-offender past the State Jail level.
Try it. Make some law.