How to use paste command recursively in a shell script

I would suggest doing the whole thing in awk, rather than using a shell loop:

awk '{for (i=1; i<=12; ++i) printf "%d%s", $1+i, (i<12?FS:RS)}' "$f1" > output

This loop runs for each line of the file and outputs all of the columns, saving the need to use another tool such as paste. The ternary operator is used to output a space (FS) between each column and a newline (RS) at the end of the line.

For the second part of your question, you can still do most of the work in awk.

declare -A companiescompanies=( [company1]=10 [company2]=25 [company3]=50 )for c in "${companies[@]}"; do    awk -v bonus="${companies[c]}" '{for (i=1; i<=12; ++i)         printf "%d%s", $i+(i==1||i==5||i==9?bonus:5), (i<12?FS:RS)}' "$f1" > "$c.txt"done

I have created an associative array containing each company name and their bonus. The loop goes through each company in the array, passing the bonus to awk as a variable (note that I'm doing this using -v rather than using string concatenation). The loop goes from 1 to 12, adding the bonus for months 1, 5 and 9, or 5 otherwise. The name of the company (the key of the shell array) is used for the output file.

I can't understand, why are you going in such complicated way. You can do it in a more simpler way:

for 2nd one:

for k in var{[@]}do awk '{printf("%.1f %.1f %.1f %.1f %.1f %.1f %.1f %.1f %.1f %.1f %.1f %.1f\n", $1+"$bonus_$k", $1+5, $1+5, $1+5, $1+"$bonus_$k", $1+5, $1+5, $1+5, $1+"$bonus_$k", $1+5, $1+5, $1+5);}' file.txt > $k_file.txtdone