None of this helped me with getting into the top room in the phoenix inn. the only key I found in Lanilor lane was the one on the planter, that gets you into the "back room" where you get cheese. I have searched all over lanilor lane and only found that one key. I have the skeleton enchanter door open, the key does NOT open both doors. this is the only quest I have left besides the 5th clue, I wish I could find the stupid key, haha. i really hope my game isn't just glitched... I don't want to start over.
This is exactly what I am experiencing. There is a key, not under the bridge, but near it in a plant. This key leads to a backdoor entrance just nearby the key to a room where you get the special cheese for the chef of the Phoenix inn (for the critics quest). I have not found any key at all that gives me access to the top room of the Phoenix inn (the locked room). I have mindread the barkeep.
Is this a glitch somehow? I did eat that talking carrot a way back

EDIT: To clarify.
The key in Lanilor Lane, near the bridge, in the planter, does
not open the top room in the Phoenix inn. It opens a backdoor where it is found. In this room you find the special cheese for the Phoenix inn chef for the quest with the food critic.