I would suggest you try somewhere like Cala Dor - its lovely walking around the marina in the evening, and there are lovely shops and restuarants in the resort. Its more upmarket and sophisticated than many others on the island but is not too quiet or too expensive. I would also suggest Soller - a lovely old town and a lovely port area to stroll around in the evening. Its also possible to take some lovely boat trips from the port area, and there is the lovely old train that runs back and forth to Palma.
To keep costs down I suggest you rent an apartment from a site such as owners direct or holiday lettings -
http://www.ownersdirect.co.uk or
http://www.holidaylettings.co.uk. This should help to keep the cost right down.
Have a lovely honeymoon!