I think the operative phrase is "before I bought the plant". Keep it watered and the light level up and it will flower. Sometimes Vandas can blast buds if the temperature gets too low, so that is a possibility.

Vanda species are more sensitive than hybrids and Ascocenda hybrids usually don't blast if they remain in the same conditions as they had when they initiated the spike. Slow is good, spike-wise, because that usually goes with long-lasting flowers.

Hello richardol. Thank you for such a quick reply. It is in good light in the south window and I am soaking it twice a week. The little bud is very green but oh so slow no bigger than 2mm and I was worried as another vanda formed a flower bud after and has already grown to over an inch.
I'm encouraged by your comments and will keep you informed. It was bought as a cross between Thongchai and sanderiana.
Thanks Hazel.