Is "all total" grammatically correct?
I think you have misheard the phrase all told. This means counting everything / everyone, e.g.
There were 500 passengers, all told.
Either that or this is an eggcorn of all told.
I have not been able to get an NGram for all total that is relevant, since the phrase pops up in many circumstances. Also, I've not been able to find instances in google books that use all total the way you have.
No. It's either "in all" or "in total", you cannot use both "all" and "total".