don't know if they have a citypass, however I did find a good way to skip the queue in the Collosseum.
Beside the Romun forum there is a place called Palantine Hill - it was the site of the old palaces. This cost e11 to see the old ruins, but your ticket also gives you access to the Colloseum (a ticket to the Collosseum is e11 anyway, so you're not paying extra). I was in Rome the other week, queued at Palantine hill for 10 mins to get a ticket, had a look around there and then strolled over to the Colleseum (not far). At the Collosseum you go through security like every one else and then walk past the line queuing for tickets (this was massive!) - at the end of the line (near the ticket office) there are turnstile gates, you enter here.
There are 'tour guides' outside the Colesseum claiming to get you in quicker if you join their tour. I've no experience of them, but when I was there they werre charging e20 per person (including entry).
hope this helps