I think a number of credits could be given, as I often see something I love and would love to do myself, but could search forever without finding everything I needed.
If someone then recreates it, you should feel honoured rather than upset.
I would love info like: this was was made by Fiona K, using XYZ pattern (designer and company), fabric from the "Poppy" range, designed by Chong a Hwang for Timeless Treasures, and quilted by Quilting by Fiona with "Poppy Border" designed by Patricia Ritter for Urban Elementz.
Wow... Now that I have written it like that it really does show that there are a lot of factors involved in making a great quilt! But if it is on display... Why not give credit where credit is due....