While on final approach for landing on runway 27 at his destination airport, the pilot of a PA-34-200T was advised by the control tower of "18 mph [wind] gusts out of 270" degrees. After touchdown the airplane rolled for "several yards," then "ballooned up and came down," at which time, the windshield broke. The airplane bounced once again, touched down, and rolled out, completing the landing. Post accident examination of the airplane by a Federal Aviation Administration inspector revealed that the airplane was substantially damaged.