I believe my snapdragons got rust fungus. (pictures attached) These were all grown in the same bed and had just reseeded from last year, so not particularly spaced well.  They came on strong and I began to notice some had small yellow spots on the leaves.  This continued to become larger spots with deeper yellow and some brown spots and some stalks became limp.  I have since cut down all of the snapdragons in the bed and also a hollyhock zebrina showing similar symptoms. 

I tried to remove all leaf debris but certainly did not get  100 percent of it.    I also use bark mulch in the bed that is still there.  Within that bed I have  a number of other plants growing including coneflower, butterfly weed, hibiscus,  and tall phlox.  Annuals including zinnia, nasturtium, ageratum, and  lantana. There are also some dahlias planted in there that started to show some brown spots on the leaves.  (dahlia visible in first picture towards middle left side).  

After cutting back and removing as much of the snapdragon debris that I could, I sprayed the area with Bioadvanced Rose and Flower spray which lists rust as one of the diseases it controls. I also plan to use Neem every 7-10 days.  

Is there anything else that I could/should do to get rid of the fungus in this garden bed?

Thanks for your help!