I always thought that in order for neos to set their bloom spikes, they have to go through the cold temp/dry regiment in the previous year post the growth season? If you only had them for about a year, and bought them non-blooming to begin with. It is possible that your plant hasn't gone through the full cycle while adjusted in your care.
I found my new plants usually took at least a month or two to adjust to my growing condition before I can begin to track its growth/spike cycle. I grow mine strictly indoor under lights in the kitchen with standing fan blowing from 10ft away 24/7. (the standing fans/ceiling fans are hubby's idea of keeping house cool in the TX hot weather, my neos are happily reap the benefits of constant air circulation