A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven't already taken a bonus action this turn. You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action.

It only stipulates that a Spell cast as a Bonus Action locks off any Action Spells from being cast that turn that isn't a Cantrip.

But, 2 leveled spells cast as Actions is fair game.

It's pretty strong, and it's why the 1DND play test has changed Action Surge so that it can only take the Attack, Dash, Disengage, and Dodge action