Tiefling Variant Heritages and Fiendish Sorcery

Given the variant heritage of the Tiefling, is it possible to adjust the Fiendish Sorcery trait for the relevant Sorcerer Bloodlines?

Daemon Spawn - Daemon Bloodline
Div Spawn - Div Bloodline
Rakshasa Spawn - Rakshasa Bloodline

Not for the first two, but there's a feat to expand fiendish sorcery to cover the rakshasa and shadow bloodlines.

In a home game, though, I'd totally allow it. ^_^

Only as a (perfectly reasonable) house rule.

There is nothing that requires a Tiefling sorcerer to have the "relevant" bloodline to benefit from Fiendish Sorcery.

A Demon-blooded Tiefling would get the bonus if they had the Infernal bloodline. Even with Improved Fiendish Sorcery, a Div-blooded Tiefling would get the benefit for the Shadow bloodline.

Restricting the benefit of Fiendish Sorcery to only the bloodline related to the tiefling's heritage would be a (reasonable) houserule.

Allowing Fiendish Sorcery to apply to appropriate bloodlines in addition to Abyssal, Infernal, Raskshasa, or Shadow is also a (reasonable) houserule.

Personally, I would use both rules. Tieflings get the bonus if they have the equivalent bloodline.

Devil - Infernal
Demon - Abyssal
Kyton - Shadow
Rakshasa - Rakshasa
Oni - Oni
Div - Div
Daemon - Daemon

For Asura, Demodand, and Qlippoth I would pick a "close enough" bloodline until such time as they may get their own.
Asura - probably Div or Infernal
Demodand - Abyssal or Protean
Qlippoth - Aberrant or Abyssal (possibly specify the Brutal wildblood bloodline)

@Samasboy1
I like that idea, makes more sense too. I'm gonna ask my DM to incorporate that.