if the ATF classifies it as a firearm then certainly the TP&W will also.
This is straight from the 2005/06 Outdoor Annual
Archery and Crossbows
(see Artificial light, below)
Only the archery and crossbow equipment prescribed in this section may be used for taking game animals or game birds. Crossbows are not lawful for taking migratory game birds. The prescribed archery and crossbow equipment may be used during any general open season. Archery and crossbow equipment may not be used to hunt deer during the Muzzleloader-Only Deer Season. It is unlawful to be in possession of a firearm while hunting with a broadhead HUNTING point during the Archery-Only season, except a person licensed to carry a concealed handgun in Texas may carry a concealed handgun. NOTE: A firearm may be possessed in camp, in a motor vehicle, or while hunting lawful game other than whitetail or mule deer and turkey (e.g., exotics, feral hogs, squirrels).
Nongame Animals: Archery and crossbows are lawful for non-protected nongame animals.
Longbows, compound bows, or recurved bows:
must have a 40-pound minimum draw at the time of hunting, when used to hunt turkey and all game animals other than squirrel.
that are equipped with a device that allows the bow to be locked at full or partial draw are lawful during any season when lawful archery equipment may be used.
Crossbow:
Any person may use a crossbow to hunt game animals or game birds (except migratory game birds) during a general open season or Eastern spring turkey season. Telescopic sights are lawful.
ONLY a person with an upper-limb disability may use a crossbow to hunt deer and turkey during the Archery Only Open Season, provided the person, while hunting, has in their immediate possession a physician's statement certifying the extent of the disability.
An upper-limb disability is a permanent loss of the use of fingers, hand, or arm in a manner that renders the person incapable of using lawful archery equipment.
A crossbow is lawful for game animals and game birds (except migratory game birds and as provided above), provided:
the crossbow has a minimum pull of 125 pounds;
the crossbow has a mechanical safety; and
the crossbow stock is not less than 25 inches in length.