What are the ingredients? Is this made from coconut or is it a synthetic fragrance?

Unfortunately there is no such thing as a coconut essential oil all coconut fragrances are synthetic. :)

Is this is a pure oil that can be used in an electric water-filled diffuser? The information is vague.

The front of my bottle says it’s a “premium fragrance oil”. The back says uses are: “soaps, lotions, butters, candles, bath salts, incense, perfumes, massage and body oils, aroma diffusion, bathing.” I don’t use diffusers...but it sounds like you can.

Can this be used for bath bombs?

I've used nothing but these oils for my bath bombs. They're amazing!

Are these phthalate free?

According to their website: "Our entire line of fragrance oils are Premium Grade, also known as Cosmetic Grade, which means they were formulated for, and deemed safe for use in topical applications per FDA and IFRA guidelines and standards. Additionally, all the aroma compounds used in premium grade fragrance oil manufacturing are rigorously tested and approved by the FDA for this usage. Our line is also phthalate, paraben, and acetone free. Though you can use our oils for diffusion, they are actually made specifically for cosmetic applications like soaps, lotions, bath bombs, perfumery, and hair products."