Ane awalnya rumit sekali mikirnya ... syukurlah ketemu link ini 
http://stackoverflow.com/questions/17306358/golang-removing-fields-from-struct-or-hiding-them-in-json-response

Ternyata cukup serahkan pada map[string]interface{}, sudah bisa kirim variable apapun, sepuasnya ke templates

  func WkTagViewHandler(w http.ResponseWriter, r *http.Request) {
          
          tagName := mux.Vars(r)["tag"]
          
          funcMap := template.FuncMap{
              "safehtml": func(text string) template.HTML { 

                  text = text + " "
                  text = strings.Replace(text, "<", "<", -1)   
                  text = strings.Replace(text, ">", ">", -1) 
                    
                  text = strings.Replace(text, "
", "
", -1) 
                  text = strings.Replace(text, "
", "
", -1) 

                  regexPagar, _ := regexp.Compile(tagPattern)
                  tags          := regexPagar.FindAllString(text, -1)

                  for _ , value  := range tags {
                    
                    tagAscii  := strings.Replace(value, "#", "#", 1)
                    tagOnly   := strings.Replace(value, "#", "", 1)
                    text = strings.Replace(text, value, "" + tagAscii + "", 1)
                  }

                  return template.HTML(text) 
            },
          }
          templates := template.Must(template.New("").Funcs(funcMap).ParseFiles(templatePath + "webkoe-base.html", templatePath + "webkoe-tagview.html"))
          
          var results []Blog
          err = MCol.Find(bson.M{"tag": tagName}).Sort("-date").Limit(1000000000000).All(&results)
          if err != nil {
              panic(err)
          }

          finalResult := map[string]interface{}{
            "tagName" : tagName,
            "tagList" : results,
          }
          err := templates.ExecuteTemplate(w, "base", finalResult)
          if err != nil {
              http.Error(w, err.Error(), http.StatusInternalServerError)
          }
      }