At this time the only way to view a lists of comments is in the Export All Data. The file name is comments.csv that will show all comments in all trainings. If users have roles that do not have permission to Export All Data, they will not have access to this. At this time, notifications are not sent out to the author when comments are made.
Our team would love to see the ability for authors to opt-in to notifications from their courses, when learners leave comments.
Other Bridge customers seem to support this idea, too: https://community.bridgeapp.com/message/1449?commentID=1449#comment-1449