Whether it's as important now or not is a different matter I suppose, with various targets for the language (including other VMs), but I don't think it's in dispute that originally the extensive java ecosystem was core to what clojure was, and was designed to be.

...but hey, don't take my word for it:

    The net result is that the prospects for Clojure going forward are
    very good. The core model of Clojure has held up well and continues to
    appeal - accessible, robust, thread-safe, efficient dynamic functional
    programming, on a world-class infrastructure, with a huge set of
    libraries. Oh yeah, and it's great fun! 

    - Rich Hickey, 2008
    https://groups.google.com/forum/#!topic/clojure/2CA_H58Cbo0