The public treaty did that. The private treaty, however, did something different. In it Santa Anna specifically agreed to formally acknowledge Texas' Independence when he returned to Mexico city:
"He will so prepare matters in the Cabinet of Mexico that the Mission that may be sent thither by the Govern- ment of Texas, may be well received, and that by means of negociations all differences may be settled and the Independence that has been declared by the Convention may be acknowledged"
It also specified what the boundaries, or "limits," of Texas' territory were to be:
"A treaty of Commerce, Amity and limits will be estab- lished between Mexico and Texas. The territory of the latter not to extend beyond the Rio. Bravo del Norte."
The war had nothing to do with the Texas border and everything to do with the expansion of slavery.
Now that's odd, considering that the only reason the war happened was the fact that Mexico marched a hostile army of several thousand men across the Texan border, as it had been doing against Texas on a regular basis every year or two for the previous decade, and used that army to attack an American troop encampment. As I said previously, debate to your heart's content about the legitimacy of taking the territory from New Mexico west. But as far as the war's start and primary purpose goes, it was a legitimate response to an invasion of American territory and an attack upon the State of Texas.
And Al Gore signed the Kyoto Treaty. Does that bind us to the enviro-nazi sacm? No. The Senate has never ratified it and never will. The Mexican government never agreed to Velasco. Santa Anna did not have authority to commit the Mexican Government. Even at that, Velasco didn't define the border. It just said that Mexican troops would stay on the other side of the Rio Grande and Texican troops would not go within 5 leagues of the Rio Grande.