Do encantment auras trigger heroic because it does say target ! But it is a spell that targets a creature?
If it says target creature.
And you're casting it on you're creature.
As long as your creature is a legal target
(No protection from color or something wonky)
Heroic triggers
Yes, when an "enchant creature" aura is first cast to attach to a heroic creature you control, it does indeed trigger heroic. This includes Bestow.
As a note here auras only target when cast from hand. If they enter any other way you choose a legal permanent to put it onto. This gets around hexproof things. An example of this would be {show and tell}
Edit for relevant rule:
303.4f (http://imtgapp.com/forum/index.php?action=imtg;area=rule;number=303.4f): If an Aura is entering the battlefield under a player's control by any means other than by resolving as an Aura spell, and the effect putting it onto the battlefield doesn't specify the object or player the Aura will enchant, that player chooses what it will enchant as the Aura enters the battlefield. The player must choose a legal object or player according to the Aura's enchant ability and any other applicable effects.