...but neither worked.
What didn't work?
Post a screen grab of a 2-Up Save for Web dialog with the settings you are using.
Your original is not showing transparency (Is its background layer white?) It should look like this:
The checkerboard indicates transparent areas in the file.
Also, if you want to float this over other colors... you may want to choose a different Matte Color than white, or use PNG-24 which supports 8-bit transparency.
What's the process of getting the image background to first show that transparent pattern? I've tried a few things but nothing worked. Can you provide the steps? I brought the logo in as a tif from Illustrator and saved it as a psd. Thanks.
Go back to Illustrator and copy the artwork. In Photoshop, paste it into a new Transparent file.
(After copying the art in AI, In PS go File>New> Preset: Clipboard. Background Contents: Transparent)
If your current TIFF file has the art in its own layer, just turn off the visibility of the white background layer and Save for Web.
I tried your first suggestion but the resulting image has poor resolution. I'm not that familiar with Illustrator so I can't figure out how to turn off the white layer.
I just figured out a way to save a high quality image with a transparent background in Illustrator. I first saved the file as EPS, then selected Preview Format and Tiff 8-bit color, which allows a transparent background. Whew!
Thanks for your ideas!