There is no root deity of Jambavan. Every Vanara was created by some deity taking inspiration from Jambavan himself. Jambavan was created suddenly from Brahma's yawn.
From Valmiki Ramayana Bala Kanda Sarga 17 (Translated by Desiraju Hanumanta Rao & K. M. K. Murthy)
pūrvameva mayā sṛṣṭo jāṃbavānṛkṣapuṅgavaḥ |
jṛṃbhamāṇasya sahasā mama vakrādajāyata |...
According to Kurma Purana, the bridge will exist as long as the earth is there.
In the 21th chapter of the Purva Bhaga of Kurma Purana, Ramayana is narrated in brief.
With the mere look at the Rameshwara Linga, all the sins of a person
are washed out. There is not a slightest doubt about it. Till the
mountains are there on earth and the earth remains,...
Does that make Ravan the grandson of Tadka? Do the scriptures mention Sund and Sumali to be the same person?
As per Valmiki Ramayana, NO:
Tataka was daughter of a yaksha named Suketu. She was married to Jambha's son Sunda. Tataka and her son Mareecha attained demon-hood due to curse of sage Agastya. ~Valmiki Ramayana: Bala Kanda: Sarga 25
On other hand ...