There is NO way to rid yourself of the bubbles........unless you use faux flowers.....and run the risk of the dyed fabric turning the water.
What causes the bubbles to form is transpiration..........which in simpler terms.....is how the flower breathes. Tiny pores on the petals called stomata open and close to let carbon dioxide in and oxygen out........the tiny bubbles of air stick to the petals and give off the appearance of little sparkles.
Just SELL that effect to the customer..........tell them that as the flowers sit in the water, almost as if by magic, tiny little bubbles will start to form on the edges of the petals.....some on the petals, and even some on the leaves if there are any. Add an acolyte or two in the vase to really make that sparkles glisten.......Your guests will be saying WOW all night long.