Did the hyoid bone of Australipetichus afarensis have a hyoid bulla?
Short answer:

Yes.

Longer but still short answer:

H. heidelbergensis and H. neanderthalensis have a modern human-like hyoid bone. A. afarensis has a hyoid bulla similar to modern chimpanzees.

The hyoid bone is thought by some to be important in human evolution because of its position in the throat and the possibility that morphological changes in the hyoid were important for the development of speech. However, this view is not without controversy, and it is probably not sufficient to use hyoid bone morphology as a definitive marker for development of speech similar to modern humans, though it may be suggestive.

Some quotes from two references on the morphology of the hyoid of A. afarensis:

Alemseged, et al. 2006:


  [the hyoid of A. afarensis] "...is
  most similar to that of juvenile African apes, and unlike that of
  modern humans11,12. The exposed greater horn is slender, and the
  body is expanded anteriorly, forming a bulla that is deep relative to its
  breadth and height..."


Steele, et al. 2013:


  "...the Dikika juvenile australopith hyoid is deep for its height (Figure 9) and width and is morphologically chimpanzee-like. This similarity applies both when comparing only subadults from the three extant species (Figure 9A), and when comparing across all observed age classes (Figure 9B..."




References:

Alemseged, Z., Spoor, F., Kimbel, W. H., Bobe, R., Geraads, D., Reed, D., &amp; Wynn, J. G. (2006). A juvenile early hominin skeleton from Dikika, Ethiopia. Nature, 443(7109), 296-301.

Steele, J., Clegg, M., &amp; Martelli, S. (2013). Comparative morphology of the hominin and african ape hyoid bone, a possible marker of the evolution of speech. Human biology, 85(5), 639-672.