No, it isn't. Oceanspray belongs to the Rose family, while hophornbeam is in the Birch posse. Oceanspray is a rarity here but several other related 'sprays and spireas exhibit extremely solid and dense, uniformly white wood that is very hard to break (also a chore to season without checking). Kyle (Pothole Primitive) from the PP forum has made some oceanspray bows and looked into the history of it's use for bows in the Northwest. For many tribes in the Basin area, oceanspray was the preferred selfbow material.
Tuukka