Overwrite field theme function from within form alter I'd like to modify the html of a form field from hook_form_alter(). Any hook for this one?
Your question itself the answer, inside
 hook_form_alter use the following 

$form['field_job']['und'][0]['#prefix'] = 'yours html'


and $form['field_job']['und'][0]['#suffix']='yours close tags of html' this html will wrap field.