Amino Acid Composition is a very broad term. To some it means tRNA/codon usage, which is usually best answered with a specific assay.
There's also bioinformaticy-ways to get an estimate of codon usage using the sequenced genome, counting 3mers either for the whole genome, or anchored on the first base of genes with non-overlapping 3mers. But remember this isn't really the same as codon usage as the amount of transcription of each gene is not taken into account. A "weird" gene with "weird" codons that is rarely transcribed would get as much weighting in such a table as a constitutively expressed housekeeping gene.
A long long time ago, I used to get my codon usage tables from http://www.kazusa.or.jp/codon/, which i presume is still relevant. But if you are just looking for a dataset where you can ask "how much of X is there in this organism" where X is some arbitrary fragment of DNA, then the only tool I know that can make use such a dataset is ACGTrie which I wrote and no one uses (not even me), so good luck with that :)
The protein content of a given bacterial cell varies substantially with environmental conditions and cell life cycle (whether it is dividing or not). Accordingly its AA composition varies. You can measure the AA composition of a bacterial culture grown under certain conditions, but you cannot calculate it. Maybe you mean codon usage in the genome?