gistfile1.txt

<?
echo '<div id="info_telefone" class="info_telefone" data-array="0">';
echo $this->Form->input('ClientesTelefone.0.telefone', array(
    'before' => '<div class="section row mb10"><label class="field-label col-md-2 text-center">' . __("Telefone") . ':</label><div class="col-md-3">',
    'between' => '<label class="field prepend-icon">',
    'after' => '<label class="field-icon"><i class="fa fa-phone"></i></label></label></div><div id="divBtnAddTelefone" class="col-md-3"><button id="btn_add_telefone" type="button" class="btn btn-info btn-alt btn-block"> + Adicionar Telefone</button></div></div>',
    'required' => false,
    'class' => 'gui-input clientes_telefone fone',
    'label' => false)
);
echo '</div>';
?>

$(function(){    
    var clonedInput = $('#ClientesTelefone0Telefone').clone();
    $('#btn_add_telefone').click(function(e) {
        e.preventDefault();
        var num = $('.info_telefone').data('array');
        var newNum = new Number(num + 1);      // the numeric ID of the new input field being added
        $('#info_telefone').data('array', newNum);
        var newElem = clonedInput.clone().attr('id', 'ClientesTelefone'+ newNum +'Telefone').attr('name', 'data[ClientesTelefone][' + newNum +'][telefone]');
        newElem.children(':first').attr('id', 'ClientesTelefone' + newNum +'Telefone').attr('name', 'data[ClientesTelefone][' + newNum +'][telefone]');
        $('#ClientesTelefone'+num+'Telefone').after(newElem);
        $('.fone').mask('(99) ?99999-9999');
    });
});