Do ACS and RSC journals have identical credit in a tenure-track application? I am a postdoc in chemistry and have published 15 papers in RSC journals. I hope to publish about 8 papers during the next year and then apply for a tenure-track position in the US.

My group leader strongly prefers RSC journals. Both ACS and RSC have similar titles. As I compared, they publish similar numbers of papers with similar impact factors.

Since I want to apply for a position in the US, is it beneficial for me to publish some papers in the ACS journals or it is OK to have all my publications in the RSC journals? 

ACS: American Chemical Society
RSC: Royal Society of Chemistry (UK)
Given reputable venues like these, you should expect a good department that you'd want to be a part of to pay attention to the substance of your work, rather than splitting hairs on whether they like one society better than the other.

Not all departments will do this, of course.  For example, I know of at least one department that discounts all journals except ones published by its favorite society.  Do you really want to be part of such a narrow institution, however?