No, it's not true. But it should be. Bush's ranch is almost 1,600 acres, whereas the Astrodome is only about 9 acres.
So come on, Mr. President. You want to make up for playing the guitar and doing photo-ops while New Orleans is drowning? Here's your chance. Get Air Force 1, 2, 3, 4, ad infinitum down there. Borrow all your country music star friends' tour buses and eighteen-wheelers. Load everyone up and take them to Crawford!