Is there a way to learn potion recipes and spells faster?

Only way I can think of is to take 1-2 sim days and practice magic as much as possible/experiment on the cauldron. Every report I've seen of people who've powered through ROM says they learned most - if not all - their magic this way. (I personally haven't found this method to be particularly more effective than asking the Sages daily, but I also don't use the Needs Potion like water either.)