Basically, I think the term artisan refers to handmade...so as long as something about your piece is handmade or put together by you, you can consider it artisan. I guess technically something that is manufactured using something handmade (like mass produced necklaces using handmade beads) could be considered artisanal, but I would more likely call it a manufactured necklace made with artisanal beads. But that's just me.
In some ways, I suppose it matters to a certain extent what type of jewelry you make, especially if you want to sell it, because your customers may want to know. However, at the same time, I don't often see people (customers) wondering what specific type of jewelry they are buying. I don't see any reason that you absolutely have to define your type of jewelry, or to make sure you are within a specific type. Just make what you love, and all the definition/type/style stuff will work itself out in your own unique way.
I don't know if that was helpful or not, haha.