Targeted job applications are usually more effective that those which are general and not specific. If the employer is looking for a potential employee with specific skills then it would be wise for a job applicant to have a specific resume.
For example, allow me to illustrate: An Investment Banker in Sydney would not normally apply by submitting their resume and covering letter for a job at a child care facility and neither would a Child Care Worker in Melbourne apply for a job at a bank by submitting their CV to perform specialist banking duties. The reason why is that both jobs and industries are vastly different and irrelevant. The target market for the investment banker are jobs in the banking and related environments. A Banker could work for a local, community bank or a large corporate bank. A person with skills in child care could work for an office with a small approved creche facility or a local child care centre. So it is about applying for tailored and relevant roles.