do you have issues with Microsoft and thats why there's no windows app

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
Perhaps the answer is for sonos to develop one of the third-party apps and provide it free

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
Or perhaps the answer is for Windows to obtain enough market penetration to allow Sonos to develop an app that will benefit them financially.

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
How will it benefit them financially the apps they already have are free

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
It will benefit them because the larger potential market offsets the cost of developing the app. Would you spend millions to sell thousands, or would you wait until you could sell millions?

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
This usually goes the other way around, where the OEM (Microsoft) sponsors the vendor (Sonos). Likely Sonos is not on their radar (not a big surprise as Microsoft aims for Android/Apple market shares) or they can't find an agreement.
But this is pure speculation 😉

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
If it was just about the money why develop any apps, people would normally have a pc with windows or a Macbook which can control sonos
it

There are several 3rd party apps on Windows 8 / Windows Phone 8 like Phonos. 
The landscape is certainly changing but for a company of the size of Sonos its a challenge to assign developers to a platform like Windows 8 / Windows 8 Phone when they have plenty of feature requests and bug fixes on iPhone and Android in the pipeline.

Help is in sight with Microsoft's "universal development platform" for Windows which should allow Sonos to use the code from their existing Windows controller app and reuse most of it across all Windows devices including Windows Phone and XBox.

On my recent question for a Windows Phone app (after insisting - and the standard initial reply of we don't have any news) Sonos support replied that they do not have an active alpha/beta program for Windows Phone.

Interesting in the fact others have posted screenshots from developer site at Microsoft showing it. As always I guess we have to wait and see.

I hate to participate in thread necromancy, but Lamaara is exactly right. The Windows mobile share is less than 1% according to most sources at this time.

For comparison, at the rate of sales for 4Q 2016 - there would be roughly the same number of Android devices sold every day that Windows moved annually. It simply isn't worth the R&D dollars.