Is there a way to see what representations are currently displayed in PyMOL?
You can use "as" to switch to a particular style (http://pymolwiki.org/index.php/As
): 

as cartooon, 11AS and chain a


You can also hide everything, to remove all representations (http://pymolwiki.org/index.php/Hide): 

hide every, 11AS and not (n. ca+c+n and resi 5-10)


I'm a fairly expert user of PyMOL and I've never seen an API exposed which will show you what representations are being used. That's not to say that it doesn't exist, there are a variety of undocumented features and commands still.

The problem is it isn't as simple as ribbon,mesh.  Every single atom can be displaying any combination of representations, so as an API call or command, it would have to return the status of every atom in your selection. If the displayed representations are exposed somewhere they're probably in a very low level format like that, and not of use unless you're a programmer.