This sire bond isn't real at all.
Why Caroline and Vicki didn't had any problems? Caroline tortured Damon a bit(hitting him with every 墙 possible) and Vicki almost killed Elena, and others(which C'mon would happen if there was a sire bond), and both were turned 由 Damon's blood. And I think there are many others examples that we can use. Again I repeat, this is first time in the show, and many people were turned there, when "there's" a vampire sire bond. Another example can be Jenna, which was turned 由 Klaus, and there was no sire bond, because Jenna fought against Klaus.

Pure and Simple, becoming a vampire, everything Elena felt for Damon went bigger. And because the Stelena broke-up almost existed since Stefan left in S2-S3, the feelings for Stefan couldn't grow up as much as the feeling for Damon did.

IT DOESN'T EXIST AT ALL. I repeat no sire bond.

Title: To Helen [Poem of Youth]
Author: Edgar Allan Poe [More Titles 由 Poe]

HELEN, thy beauty is to me
Like those Nicean barks of yore,
That gently, o'er a perfumed sea,
The weary way-worn wanderer bore
To his own native shore.

On desperate seas long wont to roam,
Thy hyacinth hair, thy classic face,
Thy Naiad airs have brought me home
To the glory that was Greece,
And the grandeur that was Rome.

Lo ! in yon brilliant window-niche
How statue-like I me thee stand,
The agate lamp within thy hand!
Ah, Psyche, from the regions which
Are Holy-land !






-THE END-
Edgar Allan Poe's poem: To Helen [Poem of Youth]