Is Ron Weasley the master of Bellatrix Lestrange's first wand?

The concept of “master of a wand“ is only used in context with the Elder Wand.

It is true, that wands work better for their real owner as they chose them and are a good fit. And they build a bond between owner and wand the longer they are used.

But the problems of working with another person’s wand are mainly “incompatibility“ and not “being the master of the wand“. So you can easily do better magic with a borrowed wand (as Harry does with Hermione’s) that “fits“ than with a wand that was won in duel that does not fit.

And why Ollivander uses past tense: the wands are clearly not in the possession of their former owners, otherwise they would not be there... it has nothing to do with mastering he wands...

As pointed out, Ollivander says the wand belonged to Bellatrix. Therefore the wand isn't hers, So it's either Harry's or Ron's. If we trace the path of the wand:

Bellatrix looked around, shocked; she turned her wand to face Ron instead. "Expelliarmus!" he roared, pointing Wormtail's wand at Bellatrix,

So Ron is currently the master. However-

"All right!" he shouted, and he dropped Bellatrix's wand onto the floor at his feet,

So the allegiance now goes to Draco Malfoy:

Draco hurried back to her with the wands.

And Harry moments later wins the wands:

Harry took the chance: He leapt over an armchair and wrested the three wands from Draco's grip

So now Wormtail's, Bellatrix's and Draco's wands are Harry's.

Actually the above outline is incorrect. It should go:

As pointed out, Ollivander says the wand belonged to Bellatrix. Therefore the wand isn't hers, So it's Ron's. If we trace the path of the wand:

Bellatrix looked around, shocked; she turned her wand to face Ron instead. "Expelliarmus!" he roared, pointing Wormtail's wand at Bellatrix, and hers flew into the air and was caught by Harry,

So Ron is currently the master since he actually disarmed her. Harry did not.. Then

"“I said, drop them!” she screeched, pressing the blade into Hermione’s throat: Harry saw beads of blood appear there. “All right!” he shouted, and he dropped Bellatrix’s wand onto the floor at his feet. Ron did the same with Wormtail’s.

So Bellatrix tells them to drop their wands. I assume since they willingly dropped them this doesn't count as an official disarmament which explains why Ollivander later on said Wormtail's wand belongs to Ron since he won it (by actually forcefully taking it).

Anyway going on,

Draco hurried back to her with the wands.

So Draco just picked up the 2 wands: he didn't actually disarm anyone or overpower them. And Harry moments later wins Draco's wand:

Harry took the chance: He leapt over an armchair and wrested the three wands from Draco's grip

Wormtail's wand and Bellatrix's wand still belonged to Ron, Draco was just holding them. Therefore the only wand Harry won was Draco's.