Little Miss Muffet sat on her Evo Tuffet™,
Eating her soykurds and whey,
When along came a spider who sat down beside her,
Until she pulled out her warhawk and blew it clean away.It seems a perfectly valid phobia, now how badly they react to the spiderfolk will play a part in how well it pays out.
Being spooked by Spiders and kin would seem to put it solidly in the common section. So that's worth base of 5. Now how badly it affects you is next and using the Run Faster Phobia table we see the following.
SEVERITY KARMA______________EFFECTS
Mild__________3______ –1 dice pool modifier to all actions
Moderate _____5______ –3 dice pool modifier to all actions; Composure (2) Test or must get away from the source
Severe ______10 _______–6 dice pool modifier; Composure (5) Test or must flee from the source for (5 – hits) Combat Turns
So it could be worth anywhere from 8 to 15 Karma.
If they can astrally perceive them, then yeah they could freak out as they would to one on the physical plane. Ignorance (or not being awakened) can be bliss!

I would not really offer more points because while it is a bigger pool of critters it does sort of balance out a bit as you will find something falling into this category pretty much anywhere, but it does not mean you will find all of them in one location, unless things have truly gone badly.