Použít na rozsah:
$objPHPExcel->getActiveSheet()->getStyle('D1:E999')
->getAlignment()->setWrapText(true);
Použít na sloupec
$objPHPExcel->getActiveSheet()->getStyle('D1:D'.$objPHPExcel->getActiveSheet()->getHighestRow())
->getAlignment()->setWrapText(true);