I don't know if you got all the plants together in one shipment, but the term "blooming size" and "NBS" have been so bastardized by growers as to be almost meaningless. Even good growers have different definitions for these terms.
back to the phil alba, our plants are of different sib/outcrosses. this species varies greatly as to flower and plant characteristics. It is possible that plants from your cross tend to be smaller than those from my cross. Usually a 2nd growth is produced when the first is more or less mature, although occasionally you will see a plant that never seems to grow "right" have a smallish first growth and then just give up and sprout some new growths (which may or may not develop normally). I have had a grand total of 4 philippinense, a regular form that has narrow leaves and 14-20" LS at maturity, one now-deceased regular form that had wide leaves and a 12-15" LS, the aforementioned phil alba, and another one that has yet to bloom, but which has a growth at 14" or so and now a new growth.
as long as the roots are good, I think your plant will be in good shape.
venustum is a compact plant, but mature growths oughta run in the 8-14" range. it's possible that the first growth is small (and will not bloom), and hopefully the next growth will fully mature.