How consistent have the bonuses and profit sharing been. It really is just a judgement call about how likely you are to get them again. Mortgage underwriters look to see if you have gotten them 2 years in a row, and will treat them as likely to continue if you have. The same rule could be helpful to you,but of course you know your work and your company better than we do.

Also, can you make yourself a budget that has the higher rent and still comes out even or ahead if you don't factor in the bonuses? If so, you are probably in good shape even if you are above the 30% rule.