Complex sentence: In 1914, he traveled to Australia where he once again appeared in Gilbert and Sullivan operas with the J. C. Williamson Gilbert and Sullivan Opera Company (1918), and as Ali Baba in "Chu Chin Chow" (1920--21).
Split into simpler sentences: In 1914, he traveled to Australia where he once again appeared in Gilbert and Sullivan operas with the J. C. Williamson Gilbert and Sullivan Opera Company (1918 and thereafter). In Australia, Workman also played Ali Baba in "Chu Chin Chow" (1920--21).