Why did Yakov name the place 'Beis-El' again?
Peninim mi'Shulchan ha'Gra (Bereishis 28:19), Ha'Kesav veha'Kabalah (Bereishis 28:19): Yakov called three [different] places Beis Kel (Bereishis 28:19), Kel Beis Kel (Bereishis 35:7), and Elokim Beis Kel. 3
Oznayim la'Torah: He was duly sanctifying the location as the place where they would ultimately build the Beis-Hamikdash. 4
I.e. in this verse, 'Elokim' does not refer to the previous words (to teach that Elokim spoke with him), rather, to the coming words (it is part of the name of the place). The Trup supports this.
Oznayim la'Torah And that was the exact spot that David designated as the M'kom ha'Mikdash, when Hahsem confirmed his decision with a fire from Heaven and David declared "Zeh Hu Beis Elokim!". See Divrei Hayamim 1, 2126 & 22:1.
Why does the Torah repeat the phrase "the location where Hashem spoke with him" three times in the Parshah (in Pasuk 13, 14 & 15)?
Rashbam: Because Hashem spoke with him in an open place, and not in a town.
Oznayim la'Torah (in the name of the Chasan Sofer): It hints at the the three Batei Mikdash.