i would have to disagree with luckyshot on terms of a second island althogh i can see the advantages of having a wine island. I would choose a glass island to colonize for a second one providing that you started on marble.
why? after a palace upgrade to 2, a third one requires
glass
around 4.9k glass to be exact.
worried about wine? buy some! that gold has to be useful for something!
or find a trader

. the boards are really useful in trades, i am now trading with some very high ranked people as they all need my marble. LOL