How to get jobs in other cities

Hi. I am an aspiring actor from overseas and currently with a talent agency in Sydney. I have done some extra jobs for TV shows and commercials and think I'm enjoying this very much and would like more of it. I heard Melbourne has many jobs as well as Brisbane, and I am willing to travel to those cities for the right opportunities. Since my agent doesn't really chase after jobs outside of Sydney, however, I had thought about contacting local talent agencies in those cities UNTIL some people in this forum mentioned that it's best to stay with just one. So, I'm asking for your suggestions as to what to do to get more jobs not only in Sydney but also in other major cities across the country, without upsetting my agent or blacklisting myself. Is it okay to send my details to casting agencies/consultants in each city while mentioning who my agent is? If I get a job from them directly instead of through my agency, do I still need to let my agency know of it and ask them to act on my behalf? (and pay that 10% commission, I suppose???) I also thought about Showcast but I can't really afford the registration fees. For any of you out there who joined the website, did you have to pay the fees or did your agency take care of it? Thank you! =)