Augmented Elements simply put is... you get your choice of an additional simple blast of any element at an extra Burn cost of 1 if not acquired the normal way; As well as gaining the Psionic Sub-type for Psionic feats, metapsionic feats, psionic creation feats. And though not mentioned more than likely the ability to hold a psionic focus.
Expanded Element simply put is ... you gain a secondary element. Choosing the same Element grants its composite Blasts as well as your choice of an infusion or utility related to that element. While a new element grants that element's simple blast and basic use (wild talent).
EX: Prime Element: Aether
Augmented Element: chose Air
Can I then choose Utilities, Infusions and Composite Blast of the Air Element.