I've a issue with creating forms. The classes - control-label & col-lg-2 arn't rendered:

    "twig/extensions": "~1.0",
    "knplabs/knp-menu" : "2.0.*@dev",
    "knplabs/knp-menu-bundle":"2.0.*@dev",
    "knplabs/knp-paginator-bundle": "~2.4",
"braincrafted/bootstrap-bundle": "dev-develop",
"twbs/bootstrap": "3.0.*",
    "jquery/jquery":  "1.10.*"

Twig:

{{ form_start(form, { 'style': 'horizontal', 'label_col': 2, 'widget_col': 6 }) }}

{{ form_end(form) }}

output:
label class="required" for="productbundle_product_title"

As you can see, the label class has ony "required"
i expected:

control-label col-lg-2 required