It has been said that the family of George Bogle, after the pension you mentioned had been paid out, worked hard to remove all references to his Indian family from the Bogle family records and papers, which are now held at the University at Glasgow.
Even though George's wife in India was supposed to have been a princess or a daughter of a Maharaja, at the time it would probably been deemed dishonorable that an upstanding British family member would have "gone native", marrying and having children with a woman of a different race.