Good detective work on #1 - that bottle had a "Cork-n-seal" closure
#2 would be aqua not clear. It has an applied lip and dates to an earlier age - mid to late 19th century.
The bottle's origins are unclear, although one might presume that since Belize was a British colony until the mid 20th c that the bottle is British made. It very well could be.
The shape suggests liquor - perhaps scotch - although the bottle is generic enough that it could have held liquid of any number of brands.
The etched / iridescence is caused by leaching of components of the glass - decomposition if you will. It is commonly seen in bottles that have been buried.
I completed an appraisal of several hundred bottles that were found (and still resided) in a central American country - they were mostly of British origin but some American. Ships transported a lot of goods to the region. There were many great bottles in this group from the 19th and 18th centuries. These were collected 40-50 years ago - others have preceded you in the search for lost treasures.
Chris