Still belongs refers to the time of the writing of the account.

Even if son of Jephunneh is felt to be obligatory in verse 13, certainly son of Jeshunneh the Kenizzite should be deleted from this verse.

The verse may be inverted to reflect chronological order, “Because Caleb fully trusted in the LORD, the God of Israel, the city of Hebron still belongs to his descendants.” Some languages may require explicit mention of the Lord’s giving the city to Caleb: “Caleb trusted fully in the LORD, and so the LORD gave him the city of Hebron. His descendants still live there.”

Quoted with permission from Bratcher, Robert G. and Newman, Barclay M. A Handbook on Joshua. (UBS Helps for Translators). New York: UBS, 1983. For this and other handbooks for translators see here .