Glenbourne:
If you take the two elements 'glen' gaellic for literally just glen, or a valley, and bourne from the old english beorn, meaning bear
so 'valley bear' or 'bear of the valley' or 'valley of the bears'
Marbella:
Again seperate the element, mar, likely from mary/maria
bella - meaning beautiful
could be a derivative of
Mariabella, a constraction of it