If I am married in the US through our religious tradition but not through court, now I want to get married out of country, can I bring my second wife?

Significantly more information is needed in order to provide a legal analysis of ways you could sponsor a second wife for immigration benefits. First, you would need to terminate your initial marriage, and for information about the process and about your rights and obligations in a divorce, I recommend you consult with a domestic relations/divorce attorney where you live. Many factors address eligibility for sponsoring the woman you intend to marry and there really is no substitute for you and her to consult with an immigration attorney who, after learning all of the relevant information, could advise about eligibilities, options and strategies to attain your goals, and who then could offer legal representation in the often complex application process.