First let me thank you, I missed that "outerclasses" in the docs that really helped. To be clear I'm actually using Bootstrap in my theme and I was able to get the fields to layout the way I wanted them to. I'm not actually sure how your example works - data-grav-field="textarea"? But in any case I got things working by:
Frontmatter
form:
YAML
name:contactfields:-name:namelabel:Nameouterclasses:col-md-6classes:form-control input-lgplaceholder:Enter your nameautocomplete:ontype:textvalidate:required:true-name:emaillabel:Emailouterclasses:col-md-6classes:form-control input-lgplaceholder:Enter your email addresstype:emailvalidate:required:true-name:messagelabel:Messageouterclasses:col-md-12classes:form-control input-lgplaceholder:Enter your messagetype:textareavalidate:required:truebuttons:-type:submitvalue:Submitouterclasses:col-md-12classes:btn btn-primary btn-lg pull-right
Place in Content
title: Location
process:
twig: true
Contact Form
{% include "forms/form.html.twig" %}
Or Place in Twig Template
<div class="col-md-12">
{% include "forms/form.html.twig" %}
</div>