Ask Mr. Smarty Plants

Depends-which do you value most, the grape vine or the tree? Vitis mustangensis (mustang grape) is, indeed, a native of Central and East Texas. It can certainly climb up over a tree, and with its big leaves shade out the leaves of the tree, causing the tree problems and, at worst, death of the tree. When you drive through the countryside in the summer, and you see those huge mounds of vines, that is usually a mustang grape growing over whatever was there. See this page of pictures of the mustang grape from the Image Archive of Central Texas Plants from the University of Texas at Austin. The vine is deciduous, which means that in summer it will be draping over and shading your live oak, and in winter, the oak will have dry vines hanging off of it. 

If you really want to keep both the grapevine and the tree, you will need to be vigilant in keeping the vine off the tree, and be very careful not to damage the oak bark when you are pruning the grapevines. The Live Oak is susceptible to Oak Wilt, and from January to June (mainly) the nitiludid beetle that spreads the fatal fungal disease is active and looking for entrances into a tree, like pruning wounds and damage to the bark.