You can expand the top-level source folder to specify as many different workflows as you need; however, if you are using one workflow per locale, you only need to specify the workflow for the top-level folder.
If you have multiple target locales, make sure you have specified a workflow for each; otherwise tasks will not be created. You may need to select the locale check box and click Update Columns to view each locale column.
You can use the default workflow table (Management > Business Rule Linkage > Default Workflow Table) to specify a default workflow to use for each linked target locale folder. This technique saves you from having to select the workflow every time a project is created, and also enables automatic project creation (with rule creation).