"The fact that an 18-year-old can't have table wine at a family gathering is outrageous."
In many states, Texas included, a parent or legal guardian can legally supply alcohol to their own minor child, including at restaurants. (I believe this also works for spouses.)
"In many states, Texas included, a parent or legal guardian can legally supply alcohol to their own minor child, including at restaurants. (I believe this also works for spouses.)"
In other states that is considered child abuse and endangering the welfare of a minor.