Thanks for the explanation. I don't consider bouquets made from various essential oils to be synthetic. To me, synthetic means that you had to perform a chemical reaction to create the note.
http://en.wikipedia.org/wiki/Perfume#Synthetic_sources
"Many modern perfumes contain synthesized odorants. Synthetics can provide fragrances which are not found in nature. For instance, Calone, a compound of synthetic origin, imparts a fresh ozonous metallic marine scent that is widely used in contemporary perfumes. Synthetic aromatics are often used as an alternate source of compounds that are not easily obtained from natural sources. For example, linalool and coumarin are both naturally occurring compounds that can be inexpensively synthesized from terpenes. Orchid scents (typically salicylates) are usually not obtained directly from the plant itself but are instead synthetically created to match the fragrant compounds found in various orchids."
I believe, beyond the information which has been posted here, that you would have to contact the lab to get information as to which blends contain synthetics of the type to which you refer. Being new to the forum, you might not be aware of the number of rip-off artists who attempt to profit from Beth's work by duping her scents, however it is an ongoing problem. This being the case, I can certainly understand a desire to preserve the integrity and secrecy of her recipes. After all, you wouldn't ask Chanel to provide the details of the sources for their scents and I believe she deserves the same courtesy.
That said, the lab has an excellent reputation for responding to people who have legitimate allergy concerns. As someone who has broken out in hives several times when sprayed with various department store perfumes, I certainly understand the concerns of the allergic and urge you to contact them with any allergy queries. I know they've been helpful with mine. The joy of having such a broad general catalog is that there is something for just about everyone.