Because John is Jack's son, and Jack is Phil's brother, and Tina is Phil's sister-in-law, and Mary is Tina's mother-in-law . . . this makes John the grandson-in-law to Mary. (note: it is possible that John is the grandson of Mary, but the relationship descriptions are not specific that Bob & Mary are married, so that deduction cannot specifically be made)
Because Tina is Phil's sister-in-law, and Phil is the son of Bob . . . this makes Tina the daughter-in-law to Bob.
