It’s open and located in the same area. As you walk in after reception, only the right side of the lounge is open. The opening hours vary, depending on flights. Most CX flights depart from SFO either before or after midnight or both. But there’s a 13:00 flight on Wednesdays. If your JL flight is on a Wednesday, you might be able to use the CX lounge. Honestly, there's nothing to write home about the SFO CX lounge, it kind of reminds me of the old BKK lounge.