hook_field_views_data() not picked up in mymodule.views.inc
That appears to be the correct behaviour. 

If you look at the code for field_views_data():

function field_views_data() {
  $data = array();
  foreach (field_info_fields() as $field) {
    if ($field['storage']['type'] != 'field_sql_storage') {
      continue;
    }

    $module = $field['module'];
    $result = (array) module_invoke($module, 'field_views_data', $field);

    if (empty($result)) {
      $result = field_views_field_default_views_data($field);
    }
    drupal_alter('field_views_data', $result, $field, $module);

    if (is_array($result)) {
      $data = drupal_array_merge_deep($result, $data);
    }
  }

  return $data;
}


You can see it only invokes hook_field_views_data() for the module that defines the field. So in the case of (what looks like) an addressfield, the function Views will call has to be called addressfield_field_views_data().

It's more likely you're looking for hook_field_views_data_alter() which will allow you to alter existing definitions. 

But if that doesn't do what you need, you might have to actually define the addressfield_field_views_data() function yourself on behalf of addressfield (if it's not already implemented somewhere). Should be a pretty quick test to find out.