If your wife has an article 10 residence card, she does not need a visa if she travels with you. The UK's residence card for the family member of an EEA national is an article 10 card.
She is also entitled to use the EU/EEA/Swiss passports queue when she arrives in the Schengen area, even though she doesn't have an EU, EEA, or Swiss passport, because she is a "person enjoying freedom of movement under Union law."
Your marriage certificate is enough to establish her right of free movement, but it is not by itself sufficient to exempt her from the visa requirement. This may account for the variation in the advice you've received.
The freedom of movement directive is 2004/38/EC. Beneficiaries of the right of freedom of movement are defined in article 3. Paragraph 1 says:
This Directive shall apply to all Union citizens who move to or reside in a Member State other than that of which they are a national, and to their family members as defined in point 2 of Article 2 who accompany or join them.
Article 2 defines "family member" to mean, among other relations, the spouse. Article 5, paragraph 2 says:
Family members who are not nationals of a Member State shall only be required to have an entry visa in accordance with Regulation (EC) No 539/2001 or, where appropriate, with national law. For the purposes of this Directive, possession of the valid residence card referred to in Article 10 shall exempt such family members from the visa requirement.
Article 10, paragraph 1 says:
The right of residence of family members of a Union citizen who are not nationals of a Member State shall be evidenced by the issuing of a document called ‘Residence card of a family member of a Union citizen’ no later than six months from the date on which they submit the application. A certificate of application for the residence card shall be issued immediately.
The entitlement to use the EU/EEA/Swiss passport lanes is in the Schengen Borders Code.
Article 2, paragraph 5:
‘persons enjoying the right of free movement under Union law’ means:
Union citizens within the meaning of Article 20(1) TFEU, and third-country nationals who are members of the family of a Union citizen exercising his or her right to free movement to whom Directive 2004/38/EC of the European Parliament and of the Council (21) applies;
Then, in article 10, paragraph 2:
Persons enjoying the right of free movement under Union law are entitled to use the lanes indicated by the sign shown in Part A (‘EU, EEA, CH’) of Annex III. They may also use the lanes indicated by the sign shown in Part B1 (‘visa not required’) and Part B2 (‘all passports’) of Annex III.
Thus, as long as she is traveling with you or joining you, your wife is a "person enjoying the right of free movement under Union law" and is therefore "entitled to use the lanes indicated by the sign shown in Part A ('EU, EEA, CH')."