Not every author allows their vampires to have the ability to mentally dominate others, or allow all their vampires to have the power even if the ability exists in that author’s vampire world.
Some vampire domination only works upon humans, and some vampires can use their influence upon other vampires, too.
Traditionally, a human needed to be looking into a vampire’s eyes to be “caught” by that vampire’s mental dominance, and authors such as Laurell K. Hamilton have continued this tradition, although Hamilton’s heroine is resistant to vampire mental domination, allowing her to look any vampire in the eye as she wishes.
Charlaine Harris’ vampires, in the True Blood novels, don’t dominate humans, but the more powerful and oldest vampires dominate younger vampires that they have created or that look to them for orders.
How an author decides to use mental domination would depend upon how their vampires originate and operate. Are they created via magic? If so, then acquiring the ability to mentally dominate humans or other vampires when the vampire is created is certainly a possibility. But if the vampires are created through some other type of conversion process (disease, death & resurrection, replacing blood, etc) then acquiring extra telepathic abilities like mental domination become more difficult to logically justify in the story world.
Too, mental domination may simply be falling out of favour, particularly with paranormal romance authors and readers, because the talent makes vampires far more powerful and potent than humans. A vampire hero or heroine who can beckon and hold a human’s mind at will, and force them to do whatever they want, up to and including physical pleasure, sex, or perhaps even convince the human they’re in love…it takes away from romantic relationships where the couple are more or less equal, and struggling to come to terms with the naturally evolving love between them. Mental domination in such a romantic relationship would make the vampire an uneasy threat, not a lover.
One of the most emotionally intense moments in romance novels is when the hero reveals his vulnerability, exposing how he really feels about the heroine, and how helpless she makes him feel. We love those moments and anxiously wait to read them. A truly powerful vampire, however — one with the ability to manipulate others’ minds to suit himself — wouldn’t feel emotional weaknesses at all, because he can arrange people and events to suit himself. It takes away one of the essential and most desirable elements of romance novels.
So for that reason, I suspect, romance authors would be wary about including mental domination as one of the traits of their vampire heroes.
I don’t let my own vampire heroes use it…so far. Although a romance where the couple are trying to work things out around his ability to dominate could be a whole new type of story….so who knows? Maybe that’s another romance warming up in the wings!