Symfony - Como customizar un formulario generado por colecciones a twig?

public function pruebaAction(Request $request){

        $lineaMovil = new LineaMovil();

        $form = $this->createFormBuilder($lineaMovil)

            ->add('numero', 'collection', array(

                'type'   => 'integer',

                'prototype' => true,

                'allow_add' => true,

                'allow_delete' => true,

                ))

            ->add('compania','collection', array(

                'type'   => 'text',

                'prototype' => true,

                'allow_add' => true,

                'allow_delete' => true,)

                )

            ->add('habil', 'collection', array(

                'type' => 'choice',

                'prototype' => true,

                'allow_add' => true,

                'allow_delete' => true,

                'options'=> array(

                    'choices' => array(

                    true => 'Línea Habilitada',

                    false => 'Línea Inhabilitada')

                    )

                ))

            ->add('simcard', 'collection', array(

                'type' => 'text',

                'prototype' => true,

                'allow_add' => true,

                'allow_delete' => true,

                'options' => array(

                    'required' => FALSE)

                ))

            ->getForm();

        $form->handleRequest($request);

        if ($form->isValid())

        {

            $em = $this->getDoctrine()->getManager();

            $em->persist($lineaMovil);

            $em->flush();

        }

        return $this->render('admin/prueba.html.twig', array('form' => $form->createView(),));

    }

{% extends "base.html.twig" %}

{% block body %}

    <div class="col-md-12 tras"><br>

    {{ form_start(form) }}

    <div id="lista-campos"

        data-prototype="{{ form_widget(form.numero.vars.prototype)|e }}

        {{ form_widget(form.compania.vars.prototype)|e }} {{ form_widget(form.habil.vars.prototype)|e }} 

        {{ form_widget(form.simcard.vars.prototype)|e }}">

    {% for emailField in form %}

        {{ form_label(form) }}

        {{ form_widget(form) }}

    {% endfor %}

    </div>

    <hr>

    <div class="row">

        <div class="col-md-12">

            <button type="button" class="btn btn-success btn-circle pull-right" id='agregar-campo'>

                <span class="glyphicon glyphicon-plus" aria-hidden="true"></span>

            </button>

        </div>

    </div>

    <br>

    <div class="row">

        <div class="col-md-12">

            <button type="submit" class="btn btn-primary animar">Agregar equipo celular</button>

            <button type="reset" class="btn btn-danger animar pull-right">Limpiar formulario</button>

        </div>

    </div>

    <br>

{{ form_end(form) }}

</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>

<script type="text/javascript">

    // keep track of how many email fields have been rendered

    var contador = '{{ form|length }}';

    jQuery(document).ready(function() {

        jQuery('#agregar-campo').click(function(e) {

            e.preventDefault();

            var listaCampos = jQuery('#lista-campos');

            // grab the prototype template

            var newWidget = listaCampos.attr('data-prototype');

            // replace the "__name__" used in the id and name of the prototype

            // with a number that's unique to your emails

            // end name attribute looks like name="contact[emails][2]"

            newWidget = newWidget.replace(/__name__/g, contador);

            contador++;

            // create a new list element and add it to the list

            var newLi = jQuery('<div></div><br>').html(newWidget);

            newLi.appendTo(listaCampos);

        });

    });

</script>

{% endblock %}