Heresies are generally (willful or unintentional) misunderstanding points of doctrine. In that sense, Covenantalism isn't a heresy, but because it is a significant building block of other heresies (largely eschatological), I've included it here.
Covenantalism is a protestant (largely Calvinist) heresy also called Covenant Theology, Federal theology or Federalism. Covenant Theology teaches that everything God has done in dealing with mankind is done under three overarching theological (meaning not explicitly expressed in the Bible, but thought to be theologically implicit) covenants: redemption, works and grace. This is considered less a point of doctrine or dogma, and more a structure by which the Bible is organized.
Dispensationalism is a 19th century protestant eschatological heresy that uses Biblical interpretation to foresee a series of “dispensations” (periods in history) which God relates to humans in different ways under different Biblical covenants. All Dispensationalists subscribe to Premillennialism, and most (but not all) hold to a pretribulation rapture. Dispensationalists also believe that the nation of Israel (not the same as the state of Israel) is separate from the Christian Church and God has yet to fulfill His promises to the nation of Israel (Dual Covenant Theology). Dispensationalism has caused some protestants to interpret Revelation as predicting future events (Futurism), some past events (Historicism) and other to associate it with the destruction of Jerusalem in 70 (Preterism).