Does beer in bread retard the yeast?
Yeast, depending on the strain, can typically sustain in alcohol in concentrations of up to 14-18%. Some strains can actually go higher. (I personally keep a champagne yeast on hand for homemade root beer and ginger ale that goes to about 18%). Typical bottled beer runs to about 6%. 

Once started the fermentation process, at room temperature, is only slowed or stopped by CO2 build up or starvation, until the alcohol reaches toxic levels. Given the portion of beer to the overall volume in beer bread recipes, the abundance of food for the yeast and the relatively short period allowed for rising none of these factors should inhibit the yeast. 

In short, the environment in your dough will reach nowhere near 'toxic' levels during the rise.