[Vuejs]-How to render variable stored DOM Nodes on VueJS?

I believe you could use $refs, something like

<video ref="tokboxVideo" />

then

mounted() {
    this.$refs.tokboxVideo.srcObject = this.tokboxVideoElementCreated;
}

You might have better success with the streamCreated event on the session. Create a Subscriber component like below:

<template>
  <div>
  </div>
</template>

<script>
import OT from '@opentok/client';
export default {
  name: 'subscriber',
  props: {
    stream: {
      type: OT.Stream,
      required: true
    },
    session: {
      type: OT.Session,
      required: true
    },
    opts: {
      type: Object,
      required: false
    }
  },
  mounted: function() {

    const subscriber = this.session.subscribe(
      this.stream,
      this.$el,
      this.opts,
      err => {
        if (err) {
          this.$emit('error', err);
        } else {
          this.$emit('subscriberConnected', subscriber);
        }
      }
    );
    this.$emit('subscriberCreated', subscriber);
  }
};
</script>

This will insert the video element inside the component. Then you can control how the component is displayed in your app.

Check out the basic vue sample in our repos.