i want to do the same. Any new info?
The only way I found is by exporting the images from the photos app and reimporting them into Lightroom.
This answer is a bit late for daniello17 and bkimbar, but perhaps it will help someone else.
In Finder, right-click on the Photos library in your Pictures folder and choose Make Alias. Next, in Lightroom, in the Import dialog, in the Source panel on the left, select the Photos Library Alias. In the top center of the Import dialog, choose Copy to copy your photos to a new location, and in the Destination panel on the right, specify that location (and choose to organize by date if you wish).
Note that it isn't possibly to directly carry over your Photos editing. By choosing the Alias in the Import dialog, you will get (1) your original photos (raw or JPEG) and (2) for photos you edited, a JPEG copy with your editing work baked in. If you don't care about your editing work, instead of selecting the Alias, click on the triangle to the left of it to expand it, and select the Masters folder, which contains your originals.