Hello,
WC Vendors (free) is WPML compatible, which is what you have highlighted there.
Where you may experience some challenges is with the front-end pages and the dashboard in WC Vendors Pro. Not all of those pages are able to be fully translated into multiple languages, though normally do well, barring a few strings, in one other language.
Please see Jamie’s response for a better description: https://www.wcvendors.com/help/topic/pro-dashboard-in-different-languages/#post-43611
