My opinion is that it is most likely to be from IoWSG, but possibly something experimental, made during training or from the artist's shelves.
I've got a large, pink and white Stuart Strathearn Impressions vase in my mitts.
It has the coloured enamels standing fairly proud from the glass, the blue used is a pale opaque pastel, the pink blobs are not round, but large and jagged or small and elongated and the background white is kind of rough to the touch. The pink is pale and like the pastel blue, opaque.
The trails on Stuart Strathearn are very, very fine, I can't actually tell what colour they are - they look just like a line drawn with a pencil.
Piccies of an Impressions vase, showing the textures and colours of the decor.
The pattern on this goblet is right for IoWSG, even if the shape is unusual.