As far as I can see, the last post about this request is this one: https://premium.wpmudev.org/forums/topic/is-events-and-bookings-plugin-fully-compatible-with-wpml#post-182792
Now, I must say that the plugin is "mostly" WPML compatible, but it looks impossible to copy some shared data (date, time, venue, etc.), so, even though in WPML I've set to copy this data, Events+ doesn't allow me to save a translated event until I've filled this data.
Could the developer solve this issue?
Well... providing that there is still someone out-there: some of my other issues are pending since weeks.