I don't think you see what the others are saying.
What is the point of pushing a coin halfway through? Read again.
I'd be more surprised if a magician actually pushed the coin all the way through. It's maybe because you wanted to use a medium familiar to you and other magicians and in this case, you used the classic coin and bottle, and so you ended up doing this. For me, such an effect would work better with other objects, say... a pencil halfway through a table, or a finger halfway through the bottle, but the coin halfway through the bottle is a bit trying too hard.
Well actually, the "halfway through-effect" is contradicting my view on just pushing it all the way in. You might want to go for an object that wouldn't come off easily after being pushed through. A pencil pushed halfway through would easily slide itself to the other side due to its shape. I hope you understand what I'm saying.
And to take your effect literally, is there really a way to have it stuck there, as you say, forever? I mean, if you can break a bottle, bend metal spoons, smash a glass, or do any other feat of destruction, surely you can take the coin off the plastic bottle by force.
