Most definitely, Tiger's coming-of-age begins with his marriage to Urmilla. Of course, it's an arranged marriage in the Hindu tradition, and at the beginning, Tiger is simply an "illiterate peasant boy" tending to a plantation of sugar.
One of the first characters to be affected by their marriage is one of the elders who simply uses the marriage to cement Hindu traditions.
You gettam house which side Barataria, gettam land, cowwell, you go live dat side. Haveam plenty boy chile—girl chile no good, only bring trouble on yuh head. You live dat side, plantam garden, live good.
You can tell by the words of the elder that he expects Hindu traditions (that of a home and many male heirs) to be followed.
Of course, this one incident isn't the "main" example of how Tiger's marriage affects characters. In fact, the main two characters affected by Tiger and Urmilla are Rita and Joe. Rita and Joe are also married, but instead of living in a mud hut, they are in a nice flat with running water and electricity. The friendship between the two married couples breaks down all economic barriers AND cultural barriers as it reveals that even in Trinidadian culture, black couples and East Indian couples CAN be friends. Going beyond friendship, Rita serves as a midwife for Urmilla when she births her first child AND a mentor in regard to the new idea of tolerance in regard to race.
The marriage of Tiger and Urmilla also affects Boysie. Boysie notices their first tendency to reject others of a different race and, in beginning to be Tiger's mentor, shows him that "colour" and "nationality" aren't all that important.
All this business about colour and nationality [is] balls.
The marriage of Tiger and Urmilla also influences the American employers of the story when they are invited to dinner at the hut. The Americans are impressed and ready to give Tiger a promotion! (Unfortunately, Tiger drinks too much and beats Urmilla. It is when their newborn boy is born dead that Tiger builds a new house in repentance.)