"Castalia Bottling Works (1893-1904)
The Castlia Bottling Co. was established in 1893 by George Schweikhart, Jr and John A. Eberhardt. In the late 1890s Castalia was manufacturing soda water,ginger ale, weiss beer and table waters. Castalia was a larger company in operation all year round and in the late 1890s employed as many as eighteen workers during the summer. Some Castalia bottles are embossed WORKS, others CO."
Your bottle is a Weiss Beer. There are 5 bottles similar to yours in different sizes and colors. One comes in a 9" (amber) and 2 come in at 7.5" (amber). One 7 3/8" Olive Amber and 7 1/4" Black/very very dark amber. The 9" amber is listed as extremely rare and the rest are listed as very rare save one amber which is listed as average. That one should have NBBGCO embossed on the bottom.
Yours looks Olive Amber from your pic = very rare and listed at 45 bucks.
All info referenced from Roger Peters book Wisconsin Soda Water Bottles 1845-1910 The book was first printed in 1996 so the info on scarcity and values is a little dated.