Generally, you wouldn't need to update the dashtop tweeters because you've already upgraded them by fitting the JL speakers. I presume these are 2-way coaxials? You should actually disconnect the factory dashtop speakers.
Whilst running both sets of tweeters 'works', don't you now have too much treble? What's more, the JL's may be fine at high volumes, but the factory ones may be struggling and distorting.
You should actually have chosen 2-way component speakers, with woofers in the doors and new tweeters in the dashtop factory locations. Presuming you now don't want to replace the front speakers a second time, I recommend disconnecting the factory tweeters.
By the way, whay makes you want to upgrade the dashtop speakers? Is there a lack of treble? As above, I would find that surprising.