When my company has a contacts web-page what can actually be included without my consent?
If it would be on a intranet (ie. only visible inside your company), your name, picture, work email and work phone number can be put on that page. This is because it would be important that coworkers know each other and can contact each other.
On a public website (visible to anybody), the situation would be different. Basically I think nothing can be put on the web page without your consent. Everything is personal data, and there is no real reason to put it on the website. In some countries it is not possible to ask consent from employees, because it would never be freely given. In that case such a contact page is not possible at all.
However if you are part of the management team or sales team, there might be good reasons to put contact data on a public website. Those will be people which represent the company. So it might be important that (potential) customers see this information. However I can also imagine it would be sufficient to add all contact data (including a picture) just to email messages.
Now it happens to be one of the fringe benefits of the company that they pay your cell-phone upto a certain amount. Does this give them the right to publish my number on their web-site without my consent?
No, I don't see why that would change anything. If it is your private phone number, it would not even be ok for coworkers to get that phone number. Only the management might have reasons to contact you in your private time.