Let's say a magician operates in a mana flood +3 that he aligned himself to, that would increase all his magical dicerolls by 3 right? now, if he summons a spirit within that zone how is it affected? does its force rise by 3, does it sink?
or simply does the magicians alignment to the area allow the spirit to ignore the background count?

Spirits have the same Aspect/Tradition as the magician who summoned them. Thus, the spirits gets Force +3 while in the aspect. Also, other spirits not of the same tradition get -3. This is why Toxic Spirits are scary!

Spirits do not get a bonus to force due to aspected background count.

They do receive a bonus to magic based tests and drain resistance tests (SM 119).

intresting it seems that this issue isnt entirely clear afterall

Even if the book says that, Spirits are magic embodied, and +Magic = +Force (or it should be). Same reason that if there is too much negative background count the spirit will pop.

The rules are quite clear regarding the effects of background count.

Thinking that extra dice to nearly all powers a spirit decides to use is not enough of a bonus, is a reasonable opinion. I just happen to disagreee with it on the grounds of spirits already being really handy, and that boosting a F 7 conjured spirits force to 10 would not be beneficial for the games I participate in.