What I like about sleep in 5e is how it synergizes with what your allies tend to be doing; that is, dealing hit point damage. It's always annoying when a caster throws out a spell that basically ends the fight on a failed save, making the damage contribution of your allies nearly moot.
With sleep, however, you can wait until you friends beat down an enemy, and then (assuming you're careful about who has the lowest hit points), use sleep as a finisher.
Anyways...I don't use bonus action for potions. I did, but what happened was that there are too many other good uses for a bonus action, even when I made other kinds of potions available.
So my current rule is as follows:
If you have a potion in a readily accessible location (such as a potion bandolier or similar container) or it is already in hand, you can drink it with your free "interact with an item" each turn. If it is in a backpack, you can use your "free interact" to get it in hand.
Then another house rule lets you "interact with an item" as a bonus action. This does mean that if someone sets it up correctly, they could drink multiple potions in a turn.
As for potion holsters and bandoliers, however, they are clearly visible, and while I don't let enemies attack them individually (I've seen called shots like that go south once in the player's hands), you can bet if someone goes down, enemies will be happy to help themselves to free potions.
I also let enemies use these same rules, though sparingly (nothing like making players sweat when they see enemies "drinking our treasure"!).
I've also allowed a player to have a potion holster on the backside of his shield, though he does need to have a free hand to grab it.
I have other rules with regards to healing, though I've noticed that even making cure wounds better doesn't stop the players from using healing word. Bonus action + regular action, even if it's just a weapon attack or a cantrip > action used to heal. And of course, having a range other than touch is nice.
So there are concerns beyond simply the amount of healing spells can do that have to be addressed. On a side note, the proposed Divine Spark channel ability the playtest Clerics have has generated buzz among Cleric players I've talked to.