You can view them via "/ip hotspot host print where bypassed". They don't show up in the active tab because they aren't logged in - only logged in users show on that tab. You can probably filter similarly via Winbox, I'd imagine.
You cannot easily assign bypassed hosts a per user rate limit. They literally are bypassed. They are unauthorized, just like any users that haven't logged in yet, and share the same bandwidth pool with them (the one configured as a rate limit on the Hotspot as a whole).
You can use queue trees to implement per user rate limits for both unauthorized (not logged in yet) users as well as bypassed users, but you cannot differentiate between them because they're exactly the same to the router. Details on how to do that are here:
http://mum.mikrotik.com/presentations/U ... xWindt.pdf