There were several companies involved in manufacturing of decorative products such as these from Victorian times, and probably earlier, I listed a number of these from the discussed period in an earier thread.
It would be common practise to source glass and pottery from various glassworks, potteries etc.
Such companies were listed as giftware manufacturers, glass refineries, finishers etc. This is a huge area deserving more research than currently exists. Often they would mark the products with their trade mark.