You're probably gonna have problems hinging that bookcase. The back corner will get caught on the book case next to it, unless you leave a gap between them. You could leave a gap, and then cover it with a piece of trim attached to the hinged book case to hide the gap.
I'd go with the secret book that you tip off the shelf for a latch. Use a spring loaded latch on the wall inside the speakeasy, then run a small cable through eye hooks along the back of the bookcase. Take a block off wood, glue a book cover on it, hing the lower front corner of the block/book to the shelf, and attach the cable to the top back corner of the block by running it through a little hole in the back of the book case. Then when you tip the top of the block/book toward yourself it'll pull the latch on the door.
This is how I'd go...just because it's so darn cool! IMHO. But your room is already pretty darn cool!