You don't really have a trunk to speak of in either of these seedlings. What you may be referring to as a trunk is actually the bases of the fronds. The growth you see now is directly related to the specific growing conditions of each individual palm. The Filibusta you bought online may have been grown in a greenhouse or a shaded area making the seedling grow tall in order to reach sunlight. The one you dug from a lot in SoCal was likely not receiving any more than a couple of inches of rainwater a year and was likely in full sun, making it's growth more compact. You won't really see a woody trunk in any of these for a number of years. Even then, you won't see the ultimate size/width of the trunk until you have a mature palm in 10-15 years.

I doubt it's solely from weather. Mine has been in the ground for almost 2 months now and we've had similarly bad weather, even a few frosts since putting it in. My guess is acclimatization. Did you bring it out from the inside and set it in full blazing sun? I gradually introduce all of my plants outside over a period of about 2-3 weeks increasing sun exposure as time goes on. Otherwise, the leaves will get bleached. If this is the problem, it's temporary and the newer leaves will be fine.

Welcome Chad, Very nice Robusta!! Your Robusta will do fine inside in a sunny location. Just make sure you have it planted in a very well draining soil and don't overwater it. Once a month during the winter is plenty. Your Robusta will grow very fast. You can control the size somewhat by keeping it in a smaller pot, but eventually it will become rootbound and need potted up. A 7 gallon pot should do what you want to do for the next two years. The yellowing on older fronds is normal. Wait until the chance of frost is over and put it in a partial sun location. Morning sun is best. After a few weeks move it to full sun so it can enjoy the sunshine. Craig

A while back, I purchased a bunch of palm seedings (maybe 20 different species). I had also made an inquiry about a W.robusta but the nursery man didn't have one. He shipped me all the seedlings and threw in a free robusta seeding that was growing as a weed around his house. All those species ended up dying eventually. The robusta is now five feet tall (dwarfed by its container I'm sure). To boot, W. filifera (another great species) is one of those few native American palms! Enjoy!