Well, it should appear ('new message' notice do not appear only when bot
makes minor edits on user talk pages).
I don't understand. :-( As a matter of fact, my bot edited my own talk page from the same IP, but anyhow, from a different user name, so I should have got the notice.
MediaWiki has also support for 'bot' parameter, so you can decide when
your bot should be visible on recentchanges, but I don't know how it is
supported in pywikipedia.
I was told there is a &bot=0, but I think this requires editing the URL directle, and I don't know how to do that in pywiki.