Sodium Bicarbonate upps the absorption (or the absorption rate?) of adderall. Obviously I'm no expert, but it has something to do with your stomach/intestines being effected by an alkalizer or an alkaline substance. Alkalizers potentiate the effects of adderrall, that much I know.
To your question, let's say that sodium bicarbonate DOES potentiate the effects of adderall. In that case, you would get stronger positive effects from the adderall as well as stronger negative effects, such as shaking or rapid heartbeat.
Be careful, good luck. Post if you decide to do it (not recommending it), I'm just curious now.