{# builder #}
$builder->add(
            'companyphones',
            'collection',
            array(
                'type'           => new CompanyPhoneType(),
                'allow_add'      => true,
                'allow_delete'   => true,
                'prototype'      => true,
                'prototype_name' => 'phone'
            )
        );

{# scheme #}
  <table name="company_phone">
    <column name="id" type="Integer" required="true" autoIncrement="true" primaryKey="true"/>
    <column name="company_phone_type_id" type="Integer" required="true"/>
    <column name="company_id" type="Integer"/>
    <column name="company_contact_id" type="Integer"/>
    <column name="number" type="Varchar" size="30" required="true"/>
    <foreign-key foreignTable="company">
      <reference foreign="id" local="company_id"/>
    </foreign-key>
    <foreign-key foreignTable="company_contact">
      <reference foreign="id" local="company_contact_id"/>
    </foreign-key>
    <foreign-key foreignTable="company_phone_type">
      <reference foreign="id" local="company_phone_type_id"/>
    </foreign-key>
  </table>
  <table name="company_phone_type">
    <column name="id" type="Integer" required="true" autoIncrement="true" primaryKey="true"/>
    <column name="description" type="Varchar" size="100" required="true"/>
  </table>
 <table name="company_contact">
    <column name="id" type="Integer" required="true" autoIncrement="true" primaryKey="true"/>
    <column name="company_id" type="Integer" required="true"/>
    <column name="first_name" type="Varchar" size="100" required="true"/>
    <column name="preposition" type="Varchar" size="20"/>
    <column name="surname" type="Varchar" size="100" required="true"/>
    <column name="initials" type="Varchar" size="10"/>
    <column name="phone_number" type="Varchar" size="30" required="true"/>
    <column name="email_address" type="Varchar"/>
    <column name="title" type="Varchar" size="100"/>
    <column name="position" type="Varchar" size="100"/>
    <column name="branche" type="Varchar" size="100"/>
    <column name="employed" type="Boolean" default="true" required="true"/>
    <column name="active" type="Boolean" default="true" required="true"/>
    <foreign-key foreignTable="company">
      <reference foreign="id" local="company_id"/>
    </foreign-key>
    <behavior name="timestampable"/>
  </table>


{# form code #}

          <div id="contact_phonenumbers"
               data-prototype="{{ _self.widget_prototype(form.companyphones, 'Remove')|escape }}">
            {% for widget in form.companyphones.children %}
              {{ _self.widget_prototype(widget, 'Remove') }}
            {% endfor %}
          </div>

          <a class="btn-add" data-target="contact_phonenumbers">Add phone</a>

{# form add js #}
        .on('click', '.btn-add', function (event) {
          var collectionHolder = $('#' + $(this).attr('data-target'));
          var prototype = collectionHolder.attr('data-prototype');
          var form = prototype.replace(/__name__/g, collectionHolder.children().length);

          collectionHolder.append(form);

          return false;
        })

{# companyPhonyType #}
<?php

namespace Axtion\CompanyBundle\Form\Type;

use Propel\PropelBundle\Form\BaseAbstractType;
use Symfony\Component\Form\FormBuilderInterface;

class CompanyPhoneType extends BaseAbstractType
{
    protected $options = array(
        'data_class' => 'Axtion\CompanyBundle\Model\CompanyPhone',
        'name'       => 'companyphone',
    );

    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('number');
        $builder->add(
            'companyPhoneTypeId',
            'axtion_jqueryselect2_model',
            array('class' => '\Axtion\CompanyBundle\Model\CompanyPhoneType', 'property' => 'description')
        );
    }
}