Is it permissible to supplicate for a vision that portends acceptance into a specific job?

There is no harm in asking Allah for a good dream. However, it is more fitting to ask Allah with high ambition to achieve the desired outcome and to be granted the job, or something better; as the Prophet, peace and blessings be upon him, said: "When one of you supplicates, let him supplicate a lot, for he is asking his Lord."