couple of points I wanted to bring back after my trip.
1) We decided to get a taxi, as we thought our luggage would have been a bit challenging to lug that distance. The taxi was called by our hotel and arrived right on time. There appear to be several 24 hr taxi stands in the vicinity, so taxi hailing at any hour should be no problem in Grenoble. We used 3 taxis during our trip, one from the station to our hotel, where we used the taxi line waiting for us. We had 4 pax with luggage and had no trouble hailing a larger taxi that fit us and our luggage just fine. Each trip was ~10 euro. Other taxi was at about 11pm at the base of the BUBBLES. We communicated to the cable car operator that we needed a taxi to our hotel, and despite our communication challenges, our taxi arrived within minutes. Very convenient taxi system.
2) We did have a bit of a mix up after arriving to the station though. There appears to be ONE bus station with TWO parts. One part for the traditional bus system, and one part for SCNF busses. The part near the train station (southern part) have "line numbers" and leave to the two nearby airports about hourly. There are NO VALIDATION machines near this part. There was a 5:00 am bus scheduled to leave to Lyon Airport. Our tickets said our bus was to arrive at Lyon Part Dieu at 5:05. This bus arrived and it APPEARED as if this was the ONLY BUS leaving until about 6pm. The monitors DO NOT DISPLAY THE SCNF BUSSES. This was very confusing. There was a heard of people on the OTHER side of the bus station. While waiting to board, a bus arrived where those people were waiting, so I went to check while the rest of our party waited to get on the wrong bus. I saw that bus was labeled with Lyon Part Dieu and quickly retrieved our luggage and transitioned our party to the correct bus. We also happened to find a single VALIDATION MACHINE at the far northern part of the station, near where the SCNF busses appear to depart. We quickly validated, and boarded. There were at least a dozen people with tickets for this bus that were turned away. We made it just in time.
It was fairly dark when we arrived, so maybe we just missed something, but there was really no indication of how we would know to go to that bus, and from what I gathered, there were at least 10 other people who attempted to get on to the Lyon Airport bus only to be directed to the (already filled) Lyon Part Dieu bus.
Just a tip for future people who might be interested in this information.