Track field dependency with features
This is a way to it:


Add the feature exportable manually to the module.info. 
You can check the available features with the drush features-list command. You have to find the field dependency format within that list, it could be a variable that looks like your field name.
If you module.info has the new field dependency, you can update the feature drush fu myfeature_module 
Then review the generated files, maybe with git diff. You should see the change.


I am not sure what an exported field dependency looks like, there are different formats, these are examples so that you have an idea of what it would look like:

features[ctools][] = field_group:field_group:1

features[ctools][] = strongarm:strongarm:1

features[features_api][] = api:2

features[field_base][] = field_image

features[field_group][] = group_teaser|node

features[field_instance][] = node-about_page-field_image

features[node][] = about_page

features[variable][] = comment_about_page