This is what I do too: yoga for corporates as part of a wider offering. My suggestion is, as part of building your own brand, be clear on the value proposition you offer. So how is your yoga different to that of other corporate yoga and wellbeing practitioners. One thing you can consider is:
What do you want your audience to THINK, FEEL and DO when they engage with you and your classes. Get really clear on this, and then identify the businesses whose wellbeing practices and culture appears to align with your value proposition.
I’d also suggest, if you haven’t already, establishing a LinkedIn profile and get active there with content offerings. This will build trust in you and your offerings, and you’ll start to connect with your target audience.
A few suggestions to get you started, hope they help.