I noticed this post a while ago but hesitated to respond since I'm no expert. However, since no one else is offering an opinion, I'll chime in.

I think it's ok to want to explore different things. If I were you, I'd introduce the topic very slowly. Sometime when you're relaxing in bed, tell her you were curious about the whole bondage thing and wanted to know how she felt about it. Hey,with all the press about "50 shades of grey" (no comment on if it's good or not), I can't believe it would be such an odd topic to at least bring up. Also, I think how well you trust each other plays a big role in this.

I'm not sure exactly what you mean by dominating her from time to time (as far as what specific acts you fantasize about), but if you put the focus on her, then how can it not be intriguing? If she's tied up and you spend time pleasing her, and she's 'off the hook' for pleasing you, sounds good to me.