Information about Vista bicycles is elusive.
I'm lucky enough to have received an owner's manual with one Vista 10-speed I picked up last year. It was a yellow men's bike very similar to a Varsity, called an "Esquire".
The bikes were produced by the N I D A, Nat'l Independent Dealers Association. This industry group formed somewhat in objection to Schwinn's efforts in the late 60s to eliminate the small-town dealer who sold feed and fertilizer, or tractors, or cars, or hardware, or whatever alongside Schwinn bikes. Schwinn's "model store" approach made them a signature brand and a lot of money (50% of the bikes sold in America were Schwinns, right up to the Bike Boom of the 70's)... but it left out the small dealers who couldn't or wouldn't make the investment to give them a separate showroom.
So a group of investors got together, apparently with Columbia (Westfield MA) and numerous other suppliers, and put together a line of bikes. There were bikes in all popular categories. 20" bikes for little kids as well as teenagers (Stingray type bikes called Torino for boys and Colleen for girls)... 3-speeds like a Speedster or Breeze, 10-speeds like I mentioned above.
There were sales catalogs offering their products both to the public and to entice dealers to carry the line in their stores. Seem to have been sold in smaller-name chain stores. Some shops surely sold Vistas as their other brand, separate from the Schwinns. They were American made, with a lot of Columbia design features to the frames. They used parts from all the same suppliers as Schwinn or Columbia would have: (Wald, Shimano, Sturmey, Huret, Persons, Araya, Union, and most likely Goodyear for the tires.)
There is a Vista Torino 500, the top-of-the-line boys 5-speed model on my website:
http://www.bareiss.net/bikesale.html
I have a couple of NOS Vista brake cables, for what that's worth. The logo is crude but kind of cool.
I don't know how late they were in business, but they seem to have gone away by 1980 or so.
Hope that helps.
--Rob