Unless the logo is going to be used alone (without words) to represent the brand, like the Pierre Jouet flowers or the Dom Perignon shield, then words only make more sense long term because the odds are that your logo will change.
It is very common for a word/logo combination trademark registration to find itself 3/5/10 years later (at renewal time) using a different version of the word/logo combo.
In most countries, failure to use the trademark exactly as it was registered makes that trademark vulnerable to cancellation. What this means is, that if you register your wine trademark with a logo, then you need to use that logo in your labels and advertising always and forever. To not use the exact same word/logo combination, is to weaken your trademark.
In USA, for example, your renewal will be rejected if your wine label shows these differences:
The words are now in Calibri font instead of Arial
The words are now underneath the logo instead of above
The farm now has a lake.
An amendment or possibly even new filing would be required, increasing your long term trademark maintenance costs.
Stylized letters, such as a unique font/color of words only should never be filed. If your trademark is words only, why lock yourself into a single font/size/format/color ?
In most countries, the strength of the filing of a word/logo combination is primarily on the word portion. There are occasions, however, in some countries, when the word/logo combination can be used in a strategy to differentiate your trademark from something similar already in the trademark process.
When budget allows, the best strategy is to file 2 trademarks:
1) words only with no specified color/size/font/format
2) then file the logo separately
This strategy protects your accumulated rights on the word portion of your trademark (your brand name). If your logo does change, you only have to re-file the logo portion at renewal time, and your word portion grows stronger with each passing year.