Yes. If you use a single spell to target multiple creatures that each have Heroic abilities will trigger for each of them. (Hidden Strings , Triton Tactics , Coordinated Assault , Flames of the Firebrand , and Martial Glory all can do this)
It is also worth noting that if you target a single creature with multiple parts of a single spell (Phalanx Leader being targeted by both parts of Martial Glory for instance) that creatures Heroic ability will only trigger once. This is because it triggers when you 'cast a spell that targets' not when it 'becomes the target of a spell you control'
Hope that helps!