For bash I was not able to use the parameters for an alias. Therefor I created a function:

t() {
tail -f -n5000 $1 | perl -pe "s/$2/\e[1;31;43m$&\e[0m/g"
}

This function will tail the file given as parameter 1 and highlight the text given as parameter 2.
Example:
t myLog.log INFO

Martijn de Bruijn