This discussion can actually be attributed to other races as well, such as Elves, Dwarves, Fae, etc. The recessive & dominant traits stand no matter the parents. However, for this discussion it's the effect of generations in terms of bite.
As discussed in the "Disclosed: Vampiric Wounds" article, Vampires bite for two reasons; bite to kill, bite to eat.
But, what effect does generational biting have on humans?
What do I mean?
Let's take a look at the crude nitty-gritty of dominant & recessive genes. We're looking at the bare bones here, I fully realize the entire scope of genotypic & phenotypic results along with the co dominant & incomplete dominance patterns related to the discussion. But, for keeping it easy to understand let's stick to the bare bones.
1st generational Vampires look like this
2nd generational Vampires look like this
The "H" & "V" at the top represent the genes passed from a Human-Vampire hybrid parent, and the "V" & "V" along the side represent the genes passed from a pure Vampire parent. As you can see, no matter what the "V" gene is present, and will surface in some way, shape, or form no matter what. It could be dramatic, or subtle, depending.
You can see that when mated the offspring has a 50% chance of being a "pure vampire" & a 50% chance of being a hybrid.
If the child is born an "HV" as both the human & the vampire genes are dominant it creates a co-dominant situation where the offspring has a chance to be more Human than Vampire, or more Vampire than human.
If the child is born "VV" it has more than anything else, Vampiric traits. Though even in a "VV" situation the fact that the "H" was ever a consideration in the first place means there can still be Human influence in the child. That is when you delve more into the minutia & details of what genes, emotions, behaviors, etc are passed.
3rd generational Vamipres look like this
Having both hybrid parents means the offspring could be potentially mostly Human if they are "HH". As the above example showed a "VV" would result in a potentially mostly Vampiric offspring.
However, when you have two Human-Vampire hybrids the Vampiric influence is 75% likely to surface with some potential, significant influence. As with the 2nd generation, having the "V" present at all in the equation means there will be some sort of Vampiric influence, even if it is remote.
A 4th generational Vampire looks like this:
It is a pure Human & a Human-Vampire mating. The "V" is a slight influence with the probability of a "true" (VV) vampire offspring not even a possibility. The presence of Vampiric genes is 50/50. In the "HV" offspring you will see a range from slight to drastic manifestation for the Vampiric traits.
What does all of this mean?
A lot when you start looking at the effects different generations of Vampires have on their companions.
For biting to eat, this entire outline doesn't matter. But, to bite to turn, it does matter.
A pure Vampire "VV" offspring of pure Vampire parents, can bite to turn and impose far more power & endowment than a 2nd generational "VV".
"VV" - pure Vampiric parents - most powerful bite-to-turn
"VV" - 1 pure Vampire parent, 1 hybrid parent - powerful bite-to-turn
"HV" - 1 pure Vampire parent, 1 hybrid parent - influential bite-to-turn
"HV" - both hybrid parents - note-worthy bite-to-turn
The ability to pass traits & powers through the bite is dictated by generation. Basically, if you're bitten by a pure Vampire with both pure Vampire parents, you are going to receive the most for your bite. Your longevity & power is the most it will be. And from there with each generation the influence dwindles exponentially.