help with Ovid grammar in a specific clause?

Latin Learning Latin
1

Book IV, line 536: “et dis adde tuis. aliqua et mihi gratia ponto est”

Venus is pleading for Ino and Melicertes to be changed into minor deities of the sea after their plunge into it, and I understand that “aliqua gratia” is the subject and “gratia” can be rendered as “consideration” or “credit”, and mihi is dative of reference, but I’m unsure about “ponto”. How would it be classified? I presume it is ablative, not dative, but is it ablative of … place from which? …origin? “Also some consideration is (due) to me from the sea”?

2

“Some favor is mine, i.e., owed to me, from the sea” because I was born from the sea and my name in Greek means foam.

You got it right.

3

The rules of rhetoric require her to back up her appeal to his pity, which she does by adducing the circumstances of her own birth, even while scrupulously respecting their separate realms. (The et goes with mihi, me too.) Ovid never seems quite confident of his readers’ knowledge of Greek, and has to spell out the spuma-αφρος(Αφροδιτη) equation.