According to 9to5Google, it appears that the transit directions functionality is arriving as a server-side update in Google Maps for Wear OS (version 11.119.0702.W). This update will make it easier for Wear OS users to plan their commutes and navigate public transportation without having to pull out their phones. Furthermore, the addition of public transit directions further enhances the convenience and utility of the Google Maps app on Wear OS devices.
Using public transit directions with Google Maps on Wear OS (Source: Google)
In the meantime, if you do have Google Maps installed on your Wear OS watch, we encourage you to go ahead and check for any updates available in the Play Store. This will ensure you have the latest version with all the latest features and improvements.