I’ll admit I have no clue how the user-places.xbel works (seems confusing), but is it possible the parent category is hidden? For example I have some entries following the “Network” entry, and hiding the Network Entry also hides them, even if they’re not hidden themselves.
In short, does your entry show up if you right click on “Places” and select “Show All Entries”?
Is there a specific reason you’re going throught the .xbel file instead of adding it via dolphin?
You can add it from dolphin, right click on the places panel “Add Entry” and type in smb://johannes@srv-nas-pi/media/audio, select its name and icon.
Those are not the same. You are talking about the bookmarks feature of Dolphin. Those are accessible through the toolbar buttons that one needs to add or the menu.
.local/share/user-places.xbel is, well, about user places, that appear in the places panel.