There is Goodreads, where the is an Esperanto group: https://www.goodreads.com/group/show/10231-esperanto The discussion isn't very active, but there is a common "bookshelf" where one can see what others add to the group as Esperanto reading material. There are also at least three list with "best books" with Esperanto-related content.
There is also a group on Librarything: https://www.librarything.com/groups/esperanto Librarything is a site where people catalogue their "libraries".
I just read about the recurring "Esperanto sumoo, a reading event that occurs a few times a year. It also seems to have meet-ups from time to time. It seems to be an ideal location to interact with other readers - physically.