If I’m holding two days Yom Tov here in Yerushalayim, do I make an Eruv Tavshilin with a Bracha?
Yes, you should make a berachah if you are planning on preparing (cooking etc.) from Yom Tov to Shabbos.
This is just as all other matters of Yom Tov Sheini, for which you will be treating the second day as a full Yom Tov.
However, if you are staying with somebody Israeli who will be doing all of the preparations for you, you should make the Eruv (just in case) without a berachah, since he will be preparing for you.