except for the "smartly dressed" part that is. During this time of year I am a lot more likely to show up in shorts.  

 
The only thing that will attract people's attention is someone going "too far" out of their way in trying NOT to attract attention. lol

 
I can think of a dozen reasons to be bringing a bottle of wine/champagne with me to a hotel room that doesn't involve a hooker, but it's certainly one of the best reasons. lol

Carry in in an bag from a Target , WalMart or anyplace
Hell carry a cooler and put it in there  
Nobody brings their own cold beer

classic worrywart..

... worrying that the world is watching their every move.  
It's not.  
It doesn't care.

give a sh*t, I will put the wine or champagne in a backpack. I also carry some shower soap so I smell the same when I leave as when I arrived.

Shopping bags... even better, the reuseable kind you can't see through.  Cooler with refreshments.  (Keep containers sealed until you are together.)  An overnight bag,. a brief case, a backpack, gym bag.  
Do be sure the gal will drink alcohol before you bring it.  

That being said I would encourage one to use discretion in this case. Go get your self a method as seen or mentioned already. If your not comfortable with that go an get a nice brief case that can hold a bottle or half in a back where you are carrying your items for the date.  

I do this all the time so there is no question at all and If someone sees me I just look like another guest at the establishment coming and going.