Here’s the list of all the Horadric Cache legendary rewards. You can ONLY get these legendaries from the Horadric Caches from doing Bounties. This list is split up into Act specific rewards, for instance if it is listed under Act 1 then it can only drop from the Horadric Cache from doing Act 1 and Act 4 Bounties (Act 4 can drop all of them). I hope that is clear.
There are also some myths about the Caches as well, just remember that the contents of the Cache is determined when it is dropped. You can’t take a Normal Cache to Torment and get the Torment level rewards.
I have also linked directly to the d3 game guide so you can hover over the item to see the stats. On the game guide though, it gives the stats for the lowest required level for the item so keep that in mind. The stats will be much higher for the level 70 versions.
Patch 2.0.5 Update: Bounty Bags can now also drop Torment-only legendaries!
All of the Bounty Bag Legendaries can drop from Act 4.
Only the Soulsmasher I wasn’t able to find a link to it in the Game Guide. With that said, there might be more to the list and I will continue to keep an eye out for new ones. I want to keep this list as complete as I possibly can, so if you know of one that is not on the list please let me know and I’ll get it added.