Red herring here - gmaplocation datatype does not work with oracle fullstop. No cluster involved.
The fault is in assuming that the .latitude and .longitude attributes of the datatype are strings using a '.' for separation of integer and decimal part (or a floating point that will be converted using a dot).
With oracle, those values are gotten back as strings with a comma inside.
Easy fix: do the str_replace in the template.
Better fix: do a typecast in the datatype and make sure there is no php.ini internationalization setting that will affect automatic conversion from php floats to string (if there is, revert to easy fix above)