We have two different add-ins, one for outlook and one for excel,word & powerpoint. The crux of both add-ins are same. But it is listed as 2 different products on Microsoft app store. Its quite hectic for us to maintain 2 add-ins. What we want is that we can have a bundle which contains both web add-ins and publish them as a single product.
I know that both of the web add-ins will have different manifest files and it wont be possible to merge them. But is there any way that MS provides to bundle multiple web add-ins to a single product ??
You are on the wrong avenue. Office web add-ins were designed to support multiple host applications in the single manifest file. You just need to specify the supported host applications. For example, see the Hosts element for more information.
Following that way you can combine two manifests together and specify different callbacks if required.
But there is no any bundle that can do this kind of job for you. That is a very specific task which can have different outputs.