[rant]Check the world tab of the index; have you by any chance created a single object called “alcohol and cigarettes”? Then it might work to say “The clerk carries alcohol. The clerk carries cigarettes.”[/rant]
Never mind, that’s not it.
OK, with some fiddling I think you’re hitting a weird bug/behavior of topics; when you check the thing you’ve asked for against [cigarettes] (or [alcohol], depending on which is first), Inform stores that topic in “the noun.” So by the time you run the second check, it thinks you’re asking alcohol about alcohol, and the rule doesn’t run. There’s some discussion here, and there’s a uservoice suggestion that goes into it here, though I firmly believe this is a bug and not a feature suggestion. (And here’s a bug report.)