Your question is an interesting one because it touches on the
subtleties in copyright and trademark law. But here's a way to think
about it more clearly:
If you are "quoting" a source (i.e., "that was a Lalique vase" or
"That's a Tiffany window") you are providing attribution of the
original work. You are giving the original artist the credit for
their creation. (Like when you wrote a paper in school and created
your bibliographic references!)
If you are, on the other hand, "claiming" to be the source (i.e., "I
created this Lalique vase" or "I created this piece of Tiffany
glass"), then you had better have the legal right to use the trade
name owned by the company (or family or artist) in question. (As
though you plagiarized that paper by representing it as your work
when it was really copied and pasted from someone else's paper.)
So in your case, you created pieces "in the style of X" to enhance
originals by X. You are not claiming to have invented the style or
claiming original design, and you are not representing your work "as"
that "brand." Rather, your work is designed to accompany work by the
other artist and to replicate his/her style of work. Therefore, you
are attributing the original artist's work, and that all falls under
Fair Use Doctrine in U.S. Copyright law.
If you are not sure about this, you can read the law yourself
(google "fair use") and/or consult an intellectual property attorney.
Does that help?
Hand-crafted artisan jewelry