So did lost hills bunker get destroyed in the war between brotherhood and ncr?

We don't know. I doubt it.

I figured that it would given that it's location has never really been a secret and it isn't that far from Shady Sands, perhaps abandonned and then destroyed by the High Elders; don't see any reason why it should still exist though.

I figure Lost Hills may still be around, largely because it's the birthplace of the Brotherhood. They'd probably fight like deathclaws on Psycho and Turbo to protect it. The cost of taking it would be too high compared to just blockading it and keeping them contained.

i remember reading that the brotherhood (after realizing that they couldnt win) escaped into bunkers so i dont think lost hills is destroyed but the bos are hiding there just like the mojave chapter in hidden valley

I have an idea for a DLC sized mod where Lost Hills is just a siege stalemate - the NCR surround it on both sides, but can't break in because the Brotherhood's tech makes the costs too high, whereas the Brotherhood keep tunnelling out to get supplies.

If Lost Hills was taken, I have a feeling that it would have info on all their bunkers and they would have been wiped out completely or driven far, far away.

The Brothehood have been around longer than NCR. They have been all over California taking all the good tech for themselves. There was a time when the BoS traded with outsiders. Lore tells us they have their own state in NCR.

So taking Lost Hills would be alot harder than just taking one bunker. I would imagine they had many bunkers and maybe even above ground towns. The Mojave BoS chapter, ran into their bunker after they lost to NCR. They only lost to NCR because they ran out of ammo. They only ran out of ammo because they were cut off from the main BoS back west.

I think we can all say its safe to say that the BoS are on the losing end of a war with NCR. So much so NCR don't even talk about the war back West in New Vegas. Still I can't see Lost Hills falling (without a canon mention of it in game). Maybe its under seige, but I am guessing they have some awesome fire power and a mountain of ammo, keeping NCR at bay.

No one knows, but due to the importance of that location in the Fallout universe, I think it's safe to say that it was never destroyed. It's highly unlikely that it's destruction would be overlooked in Fallout canon.