> (...) are we able to simulate that neural network and see the same
  > behaviours as in the living nematode worm?

No. With biological networks, wiring diagrams are only part of the bigger picture; (electro-)physiological differences matter a lot. This is especially true for small systems in which individual neurons perform highly specialized functions. (Mammalian neurons are substantially more generic!)

So the short answer is no; the longer answer is we're slowly getting there. Key problems are lack of plausible feedback from sensory etc. systems as well as currently inexplicable in vivo/in silico disparities.