Is bowling a sport - I say yes (dependent on the level of competition) - as clarified by the following partial quote:
Bowling is highly comparable to archery, shooting, baseball/softball pitching or other accuracy based
sports where the ability to perform a skill precisely and repeatedly is the key to success.
High performance bowlers possess these abilities as do Olympic-level athletes in the sports noted above.
Are all bowlers elite athletes? Certainly not. Bowling is played by persons of all skill and ability levels: recreational beginners to the very elite. While it is considered by some to be a leisure
pursuit, bowling has long been a competitive sport among the more elite bowling athletes whether in local leagues or tournaments, or in regional, national or international championships.
Much like tennis, running, equestrian, table tennis, baseball/softball, basketball and many other
Olympic sports, persons participate for many reasons including recreation or health/fitness but do so at level far below the Olympic high performance standard.
In summary, elite bowlers possess the physical and mental attributes to consistently perform a complex sport skill such that they can roll an approximately 15 pound (6.82 Kg) ball down an
18.3 meter (60 foot) lane in such a manner that ten pins are toppled with virtually every roll of the ball. To achieve a perfect score of 300 this must be done twelve times in succession.
Though different in the requirements for successful performance of sport skills such as baseball/softball pitching, basketball shooting, archery, shooting (rifles/pistols) and even diving
and gymnastics, bowling requires precision and consistency in every execution of the technique. Failure to deliver a single, precisely rolled ball in one game or over a three-game set is often the difference between winning and losing a match. Therefore, the bowler must deliver the ball with virtually perfect biomechanical execution each and every time the ball is rolled down the lane during competition.
Look here for the entire article