You can get all 5 Perks.

[Wingsofhalo]

So as we know right now there is only 5 Perks Purchasable on the Map. If you have all 4, and you survive a monkey round without them touching a machine, you will get the bottle (this is common knowledge by now) the bottle will give you a 5th Perk.

Speculation:

Maybe if you have all 5 Perks, and you get the bottle again it will give you Double Tap.

[CheezyWeezle]

Or if you have all perks (Double Tap too, if it gives it to you) then it upgrades your perks? Or maybe you get like 10,000 points? Or a free PaP for you current weapon?

[R0FLZ]

You probably get a bonfire sale